Afraid of sex

After having a chemical pregnancy in April we just found out we were expecting again. This pregnancy already feels so much better but I can help to feel paranoid about everything. Sex is one of those things. It's sounds so silly but the thought of it terrifies me that something will go wrong. I'm only 4 weeks and 3 days which is how far I was the first time. I just wonder if anyone else feels this way?? My husband doesn't really get it and  I'm starting to feel guilty.