Brown spotting

Hey ladies! I am on cd 13 and had some twinges and slight cramps last night. This morning I woke up to brown spotting it's just a little bit but noticed it when I wiped and checked again. I have never had spotting this early in a cycle and haven't had any usual ovulation signs yet either. I'm really confused what is going on. I have been off bc pills since November. Could I have ovulated early? The last two cycles were around 30 days. Maybe this is a shorter one? Please help. So confused :/