Boyfriend doesn't want another baby...

We have two kids together and after our DD was born we put off having kids for a bit but now that she's gonna be 3 in a few months i desperately want another baby. I've always wanted a big family and he knew this from the beginning. He wasn't against it until a few weeks ago. Now he never wants to have sex and if we do he uses a condom or just says no. I was completely against having a third child until last year when we had a huge scare. I had my period for 3 weeks heavy flow with huge clots. Had to go to the emergency room for a blood transfusion. When the nurse told me that I had come in just in time or I would have gone into cardiac arrest I knew I wanted another baby. I didn't come right out then and there saying I wanted another one. I kept it to myself asking myself if I was really ready to have another one getting up at night, breastfeeding, etc. and I know I'm ready but when I told him last month he was completely against it.