Pregnant after Period?

Ni

I lost my virginity on the 26-27tg February. I took the next day pill just Incase! Then I got my period , it was two weeks early and lasted only 5 days... mine normally are 7 days. In a few weeks after that me and my mother went to a planned visit to the gynecologist, my mum found out I’m not a virgin, and the doctor told me I had an infection so I had to take antibiotics for 3 days! My mum has been freaking me out saying that I don’t need to rely on my period that woman can be pregnant and have three periods! I’ve not had any symptoms apart from being tired and the fact that my period is late for 9 days, according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>. As well I’ve had back pains like always before period for the past nine days, for a day my nipples were kinda sensitive and I had a hurting feeling in my left overie a couple of times these past nine days and I’ve been on my nerves a lot which is posing my mum off! I’ve just had my Mid Year Gcses and was in quite a stress! Could I possibly le pregnant? I’m very scared!