I think I may have had a miscarriage..?

Elli • Elli~ 19~Midwest but east coast raised~lover of memes and dogs~wiccan~self-deprecating hipster
So last week me and my boyfriend had unprotected sex for the first time and he came inside of me. Granted I had been on the pill for a little more than a week, so on some level we thought we were covered. I had just finished my period the week before so on further thinking I realized that technically I would have been ovulating. I freaked out for about two days then put the thought on the back burner, up until today. Within the last few days, I can't remember exactly when, I experienced a sharp pain in my vaginal/cervical area and today I found a brown reddish mucus in my underwear, and though I almost never spot and the pill has been known for causing that sometimes it wasn't just a regular spotting, it was a little thicker than that. I know it may be a bit too early to tell but it was a weird experience. I've know two girls personally who have had miscarriages due to the pill and it probably doesn't help that I've drinken heavily four days over the last week and that I've had about seven cigarettes yesterday and today. So I think I may have miscarried but I'm not sure?