so i've been taking my allesse faithfully and everything has been just dandy with that.
until a week ago i started taking cephilexin for my strep throat. (an anti biotic)

it was the second last day of my active pills when i began the anti biotics.
i took them for 7 days, during which time i had my period.
i took the first pill of my next pack today.
last night i had sex several times.
all of which my boyfriend ejaculated inside me.
what im wondering, is if the cephilexin could have effected my birth control enough for me to be pregnant?
or is the risk too low since it was at the end of my cycle?

and does the anti biotic significantly reduce the effectiveness of birth control?

i would really appreciate feedback on this, since im a little worked up over it.