could be preg? spotting? birth control?

i take birthcontrol, trisprintec is the generic for orthotricyclen.
i take it everyday, time sometimes differes, but is within an hour or 2 difference.
i also take an antibiotic for acne, called tetracyclin. (antibiotics can mess birth control up)
i've been having unprotected sex with my fiance a lot latley and everytime he came in me.
my last menstral period was January 14th(when i started ) and ended January 17th.

we had a lot of sex since then, and today (February 2nd) i went into the bathrooma nd pulled down my pants to see light pinkish blood on my white underwear! when i wiped nothing was there, but it was clearly blood on my undies.
im due for my period next week, at the end of the week around the 10th/11th, i bought a preg test, but cant take it til then.

my question is, is the spotting i saw implantation?
do you think that my birth control failed?

id be happy if it happened, reason im on bc is because my period werent right when i was younger and just never got off it.

Hi there

It could certainly be implantation bleeding, but the only way to find out unfortunately is to wait another week or so and then do a test, any earlier probably won't give an accurate result.