Needing advice!

I had sex a month ago with a condom that definitely never broke then got my period 5 days later but it only lasted 2 days and was very light on the 3rd, I think that was because I was stressed and overthinking. Cause I'm an over thinker I calculated when I ovulated and didn't ovulate until 2 weeks after the date I had sex and sperm only lasts for 7 days, just in case a bit went in although it couldn't of. Today I've started my period or what I thinks my period, the blood goes from pink to dark red and has been lighter. It's also came 5 days early so this could maybe be because I'm so stressed out recently with just about to start uni and with results day just being a few weeks ago