Scared my boyfriend isn’t my babies father

Before you judge just know the story first.

On June 23rd I was at a friends house where I was forced to do some things I didn’t want to do and have no idea if protection was used. I got my period June 30th through July 4th/5th (I spot a day after heavy bleeding) and everything seemed normal.

When I came back from my trip me and my boyfriend had sex July 13th (didn’t use protection) and I found out I was pregnant July 28th. When we went for my ultrasound I asked them to line the dates up and they said based on my last period I was got pregnant July 14th and I had that reconfirmed with my doctor. My boyfriend knows about what happened in June and said no matter what he will raise it but I’m so scared my son isn’t his. I know there’s pretty much no chance the baby is the first guys but It still scares the shit out of me