Late period on pill

So about a month ago, my period was late by 2-3 days. When it did come it was very light too. I took a pregnancy test on the second day of my missed/late period and it was negative. I take my pill at the same time everyday and the last time I did have sex he pulled out. I know anything is possible, but could I be pregnant even if the test was negative?

Btw I took the test 4 weeks after unprotected sex in the morning first pee

I know I may be worrying too much, but it’s been stressing me out all month. I’m so afraid that my period will be late again or missed. I’ve been on the pill for like 7 years now, so I don’t know if maybe it’s normal for it to get lighter over time.