I found out with my first pregnancy at 14 weeks, as well, that I had placenta previa. You need to take what the doctor tells you very seriously. I really am not trying to scare you but you really need to get rest. Did your doctor put you on bedrest? Placenta previa can be reversed and you are early on in your pregnancy that it definitely could change and work out just fine. My previa reversed itself after the 18th week since I was on total bedrest. Orgasms are dangerous for previa since your uterus does contract and that is what the docs are trying to avoid. Just make sure that you do not do this again and please take care of yourself. Bleeding is definitely not a good sign in Placenta Previa so you may be ok. I would call the doc and check with him if you continue to have the cramping.
Yeah, I believe that orgasm is not good for you becuase your uterus is contracting while and docs want to prevent it because you have a risk. Sorry!!!
Oral sex is not ok because they do not want you to orgasm.