I am 20 years old and I need advice?

Okay I had a miscarriage about (March 17th) 5 weeks ago. My bleeding from it stopped on Tuesday, April 15th. I started Yaz the Sunday after my miscarriage. I finished my pack last Tuesday(April 14) and just had the 4 white pills. I had unprotected April 19 (started my first Yaz pill right before) and April 20. I took the morning after April 20 and April 21 (the 12 hour interval) and continued my daily regiment of Yaz pills. Yesterday, April 21, I started having a slight brown discharge and I feel the effects of what could be a period but my mind is playing serious tricks on me. Is there anyway I could have missed something? Is there anyway I may become pregnant? Could I be ovulating within those days?