sex on the first 4-10 weeks?

Hello girls! I found out a week ago I'm pregnant and me and my husband are really happy! We had sex a couple of times but the first time was kind of painful and uncomfortable (mosthly because since then I'm really bloated/gassy and I don't know if it has something to do). Second time was great. Anyways, then a close friend of mine who got recently her baby told me that she waited the first weeks with no sex in order to avoid miscarriage because it's suppose to make the fetus not to "paste" in the uteros. (I'm 5 weeks)