I am 15 and don't want to move with my mum and I would like to know what I can do please help me I really want to stay

Not much information, but no there is nothing you can do, if parents are divorced?? You did not say, but if your mom has custody of you, you will go where she says,

Who do you live with now?

Until you are 18 you cannot go out on your own.

Why don't you want to move?

Because I might be pregnant

If your mother is your custodian, you go where she goes. Pregnancy is another issue you will have to deal with.

There are a lot of legal issues at 15 and pregnant, First you need to know and find out if you are. Then of course the legal issue of age of father, and where you live since normally sex with a 15 year old is illegal.

So, we need more information, not just one line of an incomplete sentence.