What Is Brown Spotting Post Unprotected Sex Suggestive Of?

On June 3rd (Friday) I had unprotected sex with my boyfriend (we do not use condoms ever), and 2 days later (that Sunday), at 11pm, I threw up, thus throwing up my birth control pill that was not yet absorbed into my system because I had only taken it at 9:30 that night. I took another immediately after I had thrown up, only to throw up again about an hour later. I didn t take another pill after that until 9:30 the next night. The Sunday white pill was my first pill of the second week in the pack. Since then, my boyfriend and I have had sex 3 times but he has pulled out and I very strongly believe he did not get any semen in me. I would not be worrying about this issue at all except, yesterday (Wednesday, June 15th), when I went to the bathroom at work, when I wiped there was a single smudge/spot of brownish/orange discharge on the toilet paper. I immediately started stressing out. I talked to my mom about it and she said it may be implantation bleeding, but that was the ONLY spot/smidge that I had wiped, and it didn t show up any more the rest of the day and none the next day. Me and my mother looked it up, and it is most likely hormonal imbalance because of the missed pill. I m just really stressing and would like to know what this discharge possibly is, I want to know for sure. I very highly doubt it s implantation bleeding (since it was only a singular smudge and nothing else before/after that), but I am paranoid about pregnancy and want to know FOR SURE that s not what it is. I guess I want reassured that I m ok and the discharge is something along the lines of an imbalance/mess-up due to that threw-up pill. Also, that smudge of discharge appeared exactly a week from when I start my period, as I always start on the 4th Wednesday in my pill pack, when I m on the orange pills. I can t remember if this discharge has ever happened before when I ve thrown up a pill, and I would really love some advice/feedback. So I guess my question is; If I had unprotected sex (and had taken my pills perfectly prior, and that night of sex, and the next day) and thrown up my birth control pill 2 days later, could I be pregnant?