I am 21 year old Female and I realized that my period is 5 days late. I have a regular 28 day cycle and my last period started Jan 9th and lasted for 8 days. I am sexually active but always use a condom. I was worried so I took a home pregnancy test and it came out negative. I have no symptoms of pregnancy apart from the bloating. Usually when my period is about to start my breasts get tender but no signs of that either, so I have no idea what is going on. I had an increase in discharge from my vagina but nothing other than that. Also, about 3 weeks ago I had a surgery on my ankle and had been on strong painkillers for 2 weeks, I am currently off painkillers but I was wondering if that could have affected my cycle? Please help I'm worried

You have to wait until you are at least 2 weeks late to get an accurate result from most tests. So I would wait until then to retest. And only do it right after you wake up the first time you pee that morning.

As far as why you are late... every woman will be late from time to time in her life... even if she has been celibate. Any number of things can cause a late period... including stress.