Uh-oh. That sounds a bit scary, actually. Yes, you can certainly be pregnant after a tubal - but if you are, your chances of an ectopic are rather high.
I actually think you can get a BFP up to 5 days before you expect AF, with something like a 72% detection rate that goes up to like 95% on the day you expect AF. (Don't quote me on those percentages though.)
I would test again, and if you get a clear BFP I would call your OB or midwife pronto. Even if you get a BFN I would retest in a few days unless you get AF.
Me, DH, DD1 (5/2009) and DD2 (10/2011). DS due 6/2015.
I'm not crunchy. I'm evidence-based.
Vaccines save lives.