spotting after protected sex, same day

Hii, I'v had exactly the same thing. Me and my boyfriend have had sex around 4 times and every time has been protected, the condom has never ripped, and I have always came on my period. But the last time we had sex was on 3 days ago, which was sunday, and when I work it out my perfect ovulating date would have been monday. On monday I noticed quite a large amount of brown discharge on my underwear throughout the day and then there was nothing at night. Again on tuesday the same thing happened, it's not wednesday and it is getting lighter but now has slight red/pinkishh bits in. I really don't know what it is? The last time we had sex I felt as though it was the deepest he has ever went as I am normally not very confident and am quite tense whilst doing it. So maybe it was new to my cervix? That has caused this? But i don't know. Please someone reply!

i had the same thing me and my bf had sex and yeah i felt it like the hardest and we been having sex for months without a condom but we used a condom this time it was fire and ice condom and i felt like he went in extremely deep and later that night i had bleed on my underwear and same time i had browish when i whiped what does that mean? Can it be just a reaction or mean im prego i been having this brownish for 4 days now ??? HELP