Wait, how is she already on her 3rd sugar pill if she started on the 11th of February? That was 3 weeks and one day ago, so she should be on sugar pill one. Still, the first response test claims to work 6 days before a missed period, and the 28th fits within that window. And as I said, for me, I get my period between sugar pills 3 and 4, but this varies a bit by person and brand of birth control (it used to be half a day earlier on another type). If you're girlfriend knows her normal on this birth control, that's a good standard to use.
I also once had my period start a day or two late. I wasn't pregnant, but I sure freaked out a bit and took a pregnancy test, even though I'd been using condoms and birth control. So oddities do happen. I looked at the info for that birth control, and it recommended taking a pregnancy test after two missed periods.
Again, any lasting doubts should be resolved by a doctor, preferably an ob/gyn. (Standard caveat to advice).
FYI dates that might help. We had the anal sex on Feb. 9 and she took a first response pregnancy test on the 28 and it came back negative. She also took one the 22 cause we were nervous and it was negative as well. And the type of BC she is on is called sprintec. She started it the 11 of february and is currently on her 3rd sugar pill and still no period
You're right about it being possible in general, but I think you're safe in this situation. Especially since you cleaned up after. If she doesn't get her period within 4 days of when she would normally get it (ignoring calendar months and just going by how many weeks), then it might be time to reassess.
If you're both super worried, just act like she's pregnant from the standpoint of not smoking or drinking, and eating a healthy diet, getting enough folate, etc., because none of these things will hurt her and it's a fine way to hedge your bets. And talk to a gynecologist if she's gone through the off week of pills and still hasn't gotten a period.
it can leake out the rectum and slide into the vaginal opening. People have gotten pregnant from this
You can't get pregnant from anal sex
lol
When you get your period with birth control is usually tied to the last day you took it. For me, when my last pill comes on a Saturday, I always get my period overnight between Tuesday and Wednesday. Therefore, if I started a pack late, and thus ended a pack late, I would expect my period to be delayed by the same amount. I think it might be a bit early for home pregnancy tests to register anything, but I think it's unlikely that she's pregnant. Check on a home pregnancy test how soon it should be able to detect a pregnancy, and maybe wait a couple days outside that window. If she still hasn't gotten her period, she can take it (following all the directions), and it should give you a better idea about whether she's pregnant. Or she could go to an ob/gyn, because they can do a blood test.
You really ought to use condoms for anal sex though. It's easier to transmit diseases via anal sex, the outside of the condom is probably smoother than your penis (as long as you use plenty of lube), and it just makes cleanup easier. And you wouldn't have to worry about something like this. (There's a big personal ick factor for me with bareback anal sex, but it really is safer with a condom, no matter what your ick factor is).