I Am Bleeding Brown Clots And On Ortho Tricyclen. Could I Be Pregnant Or Is This A Miscarriage ?

i have a question, i started my period on the day i was suppose to, but its brown, and all i do is pass clots. No period blood , no colors of red just dark. I always start on the same time every month im on ortho tricyclen, period every 28 days, last period was very short didnt last but 3 or 4 days..... these two have been unusal. could i be pregnant or had a miscarriage? I was in a relationship for over a year, not protection just my pills?? im nervous and have a funny feeling of this. im a mother of one.