I came off the pill... ouch

Hey guys, 

I haven't got any children, and I have no intentions of having my own.

However I feel like this is the right place to ask my question as I'm sure a lot of moms would have been through this.

I am in the process of becoming and egg donor. Which meant me coming off my pill. I was on the pill for 4 years, the one that doesn't allow you to bleed at all. I've been off it for around 3 weeks now. The pain in my lower stomach is like really bad cramps and almost like the feeling of a stitch. I haven't had my withdrawal bleed yet. I'm just curious as to if you ladies have experienced this too ? Any help would be very much appreciated TIA