He lied and lived a double life

So the man I thought was my fiancé has been lying to me for the last 2 years. We got engaged in April and shortly after that found out that we were pregnant with out first child together. Well i come to find out on Wednesday morning that he was still married and still with his wife that he had told me he had left and was in the middle of a divorce with.

I feel horrible, used, unwanted and i feel like my unborn son is just as unwanted as i am. Since finding all this out we havent seen or spoken to each other and at this point ive decided to start looking for lawyers and filing for full custody of my son.