sex whilst pregnant

Ok so I found out about a month ago I'm pregnant. I'm now 9 weeks (about).

We haven't had sex or any kind of sexual activity since I've found out as ive been a bit apprehensive 😩

Tonight we had sex. It felt amazing. But my partner didn't finish and I dont know why. This never happens. I feel like it's my fault.

Also is sex safe and should I just chill out?