Even though your sex was close to the fertile window there is no suggestion you may be pregnant. Why not run a test this weekend just to confirm.
Posting an update just because even if time passes a lot someone that goes through this could find answers and comfort. As a person with anxiety disorders it's very hard to take sth out of your mind and see clear especially when this regards health issues. So I will be completely objective here. I went to the obgyn 2 weeks after the early period I had and 1 week after the day I should have normally gotten my period. She did a transvaginal ultrasound and told me I'm not pregnant and it's a cyst. I let one month pass and didn't get my period with the early date. Now I am 6 days late took a pregnancy test and it was negative. I could see a very very faint line after looking very very closely in the darker side of the room. A line that if you try to focus on it I sometimes see it sometimes no. In the day light it's negative. I took pictures and you can't see it unless you lower the vibrance. My mom says it's 10000% negative but I can't stop thinking bad about it. I will do one more. Please If you deal with a person who has lots of anxiety just know that it's very hard for them to see clear and be free of their worries beat with them don't get mad. I know I had protected intercourse, a period (bc it lasted 5 days and I had a lot of blood for it to be typical implantation) and an obgyn telling me I'm not pregnant and a most likely negative test but I can't get the bad thought out of my mind. I will update again