I am 5 months pregnant and my bf's ex makes are lives hell! Am not allowed near there daughter and she has said she will do what ever it takes to stop that. We don't know what to do? Need some advice

If he can't make mediation work, then all he can do is hire a lawyer or let the court decide. Are they married, divorced, going through divorce, in Family Court over custody, what?
Your job is to stay out of it - totally if you possibly can. It's between the two of them.

There is little you can do. You have to rights or relations to his child. Even if you marry. The mother, assuming she is the primary custodian, can usually block your being with her child..

They are currently going through mediation at the minute so he has a solicitor/lawyer on the case. I am
Not involved at all I stay out of it bit were about 2 have a baby together how would this work if he has 2 stay out from our child?

She also rings his phone and wants me to speak on he phone... she has contacted my friends via face book to tell them things to tell me! So it's not me causing the conflict!

'how would this work if he has 2 stay out from our child?'
What do you mean? She has nothing to do with your baby and you have nothing to do with hers.
Yes, of course she is the ex from hell - you are the 'other woman' and she is trying to protect her child, both in terms of support and making sure he has a father. You knew he had a child when you got pregnant. You could be in her position someday. IGNORE her. She will stop if you truly ignore her 100%. Let it be known through others that legal advise is to have no contact at all.

What I mean is that he has to go and stay out at his mums house over night on a Saturday to have his daughter, I think the world of his daughter and I really do understand that it is hard to have another woman around. I know he had a daughter when I got with him, but surely she can't expect him to go staying out from 12 o'clock sat after noon and return to us on a Sunday evening? Believe me this woman is an ex from hell, screaming and shouting and drinking A lot in front of her she has a split personality and a control freak I guess am just f@cked really by what your saying ha! Are you on the USA by the way? Just wondering of are laws are much different? Thanks for the reply

My partner works Monday to Friday 8-5 so a weekend would be precious time he could be spending with his 2 children but the way it looks he is going to have to be a part time dad to both his children for the sake of a person that obviously is really rather selfish and has no conscience?

He 'has to' be gone from noon Sat to Sun night?
I would think he would split the weekend in half. Friday about 7 pm - 10 pm, Sat about 7 am - 10 pm, Sun about 7 am - 9 pm, is 32 hours. Half way is 16, so go there around 8 pm Sat and leave at 9 pm Sun.
Meanwhile you haven't had your baby yet, so I don't think it's unreasonable for him to stay with his daughter more, despite how hard it is on you. He has you all week even if it's only after work.
The laws aren't much too different here in the US. You haven't said what the court ordered or why he is going to his own mother's, or why you can't be near her child. Usually it takes 'something' that you did.
Somebody needs to impress on all parties involved (we can't judge from afar who is doing what) that it's in the interest of both CHILDREN for the mothers of two children to get along. Hope I'm not preaching.

No am glad of some feed back, obviously all my family and friends are on my side and hers will be on her side (that's just what happens) to save arguments I think your right about splitting the weekend or 1 child is going to loose a father! How ever his ex isn't happy with the current situation of 1 night away and always wants more! She basically wants my boyfriend to do 2 are baby what she doesn't want doing to her own (pushed out) I just thought it wouldn't be right for her to find out her dad has another child that is going to be her half brother or sister that she was stopped from seeing? I know are baby isn't here yet and it's hard 2 say. I have tried to reason with her and basically kiss her arse to keep the peace but she is t interested, she won't have my boyfriend split the weekend up it would mean him leaving is on a Saturday afternoon and returning Sunday evening, I know she wouldn't compromise with us at all! I guess it's up to the mediation or court what they grant, I just worry she will lie through her teeth and get what she wants! Just doesn't seem fair.

He needs to get this into court, but until he has a court order he has to do what ever he has to.

There is no way to make her do anything before he has a court order. He should document all of this to use in court

You can't get a court order in the uk without going through mediation 1st... you have to have a certificate to say you have both tried! I don't know if it's the same as over in the USA it's a new law now here in the UK! You just hear a lot that they side with the mother he just wants to be able to get on with his life and of am there or not for it not to be a problem but it is and there is no compromise with his ex that's the hard part!