Not Bleeding as Much as I Expected

I went to PP on Tuesday to take the first pill, then on Wednesday evening, I took the other 4 that you put between your cheeks and gums. I didn't start bleeding till about 5 hours later, and was having horrible cramps, and a little nausea. I passed 2 BIG clots, then after that my bleeding has been similar to my normal period, and I've only had a few light cramps and have had no clots. Is this normal? it's been about 20 hours since I took the pills and I have only had to change my pad 4 times, I expected a lot more! Just looking to ease my mind, I really dont want to have a surgical procedure! (I am 7 weeks)