I've been married to my husband for about two years and moved to another city. About a year go he told me that he received an email from his Ex apologizing and regreting the way she treated him when they dated for 3 years.
They've been broken up since 6 years ago and they never got in touch since that time, and this was the first time she's contacting him since then.

Things went normal I didn't object or get angry for them emailing each other and apologizing to each other for one time.

I got pregnant and in my seventh month now, and since I'm a housewife we decided me and my husband that I give birth in my hometown where my parents live and he will follow me when it gets closer to my due date.

(he had given me his password willingly without me asking for it, when we first got married). And I don't mean to spy on him or anything, but one night I just thought of checking his email and I saw an email from him to her, indicated that they've spoke and she had got mad at him for some reason and he was acusing her and telling her that she'd never changed, and they had few bak and forth emails blaming each other for the reason that broke them up.

Didn't mention anything to him at that time, and continued to monitor his emails. Few weeks after he sent her another email wishing her a happy birthday and she replied thanking him and saying that she's not upset and she's fine now. Also she informed him that she will visit the city where my husband is in (where me and him live). Her visit was going to be in June without specifying the date, he replied asking her if it will be early June is better because he might have to come to my parents hometown in case I deliver earlier than my due date.

Yesterday there was an email from her informing him about the date of her arrival and that she'll be free to see him anytime between June 2nd till the 24th. His reply was (great and suggested to meet her either on the 4th or the 5th of June)

My questions is that I'm really bothered with what's going on specially that I know he used to tell me everything before but since I got pregnant he started hiding this matter from me (don't know whether the pregnancy is the reason or maybe he started developing feelings towards her), I would like to tell him that I read everything but at the same time I don't want him to think that I was checking up on him because he might think that I didn't trust him.

Also I'm worried that if I stay quite I might risk my marriage, and I know if he makes a mistake with her I will never be able to stay with him.

Please let me know whether I should stay quite or tell him, and if I tell him what should I say about the reason of me checking his email?

I don't know what "intervening our marriage" means but I see two choices - say nothing and live with this knowledge or confess that you were into his email account and confront him. You admit you monitored his emails. This was most definitely not a one time thing.

You don't trust him (apparently for good reason) and now he won't trust you (also for good reason).

And then if you want to stay together I think you go for counselling.

That's the problem with spying - you never know what you might find and how you will handle it.

I'm an investigator. I work matrimonial surveillances. Know what I tell people? Don't have your partner watched unless you can handle whatever the investigation turns up. If you have suspicions, address them. Don't resort to snooping.

On a completely side note - I would never even dream of opening my husband's wallet and looking inside, let alone tapping into his emails!

I agree with JKT - you've put yourself in a difficult position.

I don't believe that 2 wrongs make a right, but he has been communicating with her and arranging to meet her without telling you. On the other hand, you have been checking his emails (which he won't be happy about) because you don't trust him - what else would he think?

It's going to be hard, but you have to 'fess up. Tell him the truth - what's the point of inventing reasons? Just be honest, if you are open about what happened then hopefully he'll be open in return. If it's all innocent, then neither of you have anything to fear.

Trust is integral to the success of relationships - if you both have trust issues then I suggest it's time to speak with a counsellor before things spiral out of control and you have a child in your lives to further complicate matters.

I would just keep my mouth shut and see where things go. Saying anything will not change anything for the better.
He may even tell you when the time comes that he is meeting her.

Do not jump to conclusions. He may simply just want to meet her for a coffee out of curiousity. Don't let it get the better of you.
Trust him.