Sex while pregnant?

Ok so we havent had sex the whole first trimester and im now 13 weeks with no know issues..I havent had an ultrasound since I was 8 weeks but I had spotting at 5.5w, 8w, and 10.5w..I had an appt and just heard the heartbeat last week and they said all is normal.

I've miscarried twice at 8 weeks so im very nervous to try sex but, is there a reason not to? I need opinions.

Edit to add: are there better positions for being more comfortable at this stage and does orgasm harm pregnancy??