I lost my virginity on June 30th

Hi! I’m 16 and I recently lost my virginity, I really am worried though. We used a combination of a condom and the pull-out method, however, we had (or rather attempted to) sex around 4 times within like 3 days. (He came 3 of the 4 (sorry for TMI, i just think it’s important to add for this)) On June 5th I got my period, and while it was heavy and there were blood-clots, it was short (like 2-3 days.) I researched this because normally my periods are longer (around a week or so) and this one was pretty painful and short, and apparently break-through bleeding is a thing when you become pregnant. I also have had some brown-spotting within the past few days and I’m terrified that I made a big mistake. I’m scared to go to my mom to ask for a way to use birth control, even though we’ve discussed it before. Is there any advice I could use? :(