Help please

I started my inactive pills this week on Sunday as usual. And I predicted my period to come Wednesday (today). I woke up with cramps and then they went away as the day goes. Normally when I'm on my period while on birth control this happens. I get cramps as soon as it's about to start, my period comes and then the rest of the day/week I don't have cramps. I always have protective sex and had sex last week Thursday. 
I've been taking my pills normally but on the 27th of May I forgot to take my pills with me. I didn't take my pill for the day until 9 hours later. I don't think it's implantation bleeding or anything. I'm pretty positive that I'm on my period but I'm not very certain. 
What do you ladies think?