I'm 33 weeks pregnant and I just started giving myself blood thinner injections this is my fourth child and never had to take them before. The injections hurt and they are making me vomit I'm not taking them anymore I don't even have a blood clot. They said it is a precaution because I had a blood clot at 16 when I was on the patch birth control I had three kids since never been on a blood thinner I'm 29 and have to get a my first c section