Period problem. But what happening.

I had protected  sex on 21oct but the condom had torn. But before ejaculate on he pulled away and he is sure that not a single drop was inside me. But I am tensed. I am on Meprete10 since last month everymonth d10to d25 twice a day due to irregular period before that. Last period was on exact 28th day but was only for 4days and light to medium bleeding.it was not painful like before few cramps only. But this month I had sex on 21st n finished my Meprete10 on 28th..bit before that on my 25th day I had started som brown spotting which continued for 3days n eventually led to my periods but today is second day red bleeding but very less in quality.. My second day use t b so heavy.. Also no cramps.. I'm having bleeding but it not spotting like last two days. Its continuing but very sparse bleeding no cramps. Nothing.. No sufficient bleeding. So what's the cause.. Meprete10 or what. M scared of pregnancies but my friends say m bleeding red aft Brown means m nt pregnant. But what happening.