Need some answers!!

Hey all. I am on Topamax (a migraine medication) 200 mg in the am and 200 mg in the pm... so 400 mg total daily. 2 months ago I started taking tri sprintec birth control. A few days ago I started to experience sore breasts and just last night I have had spotting and some cramping. Oh and I can not catch up on sleep to save my life. I am so tired! According to my birth control, I am not due for my period for another week.

Is there a good chance that I could be pregnant due to the topamax not making the birth control work? Should I stop taking my meds right away until I know more? I don't want to cause any problems!! Thank you... I am slightly freaking out.