No Longer on the pill

I've stop taking my birth control pill for a month now, just after I finished my last cycle. For about 2 weeks now I've been having severe cramps and back pain. I don't remember the last time it felt this bad. I spoke to a nurse at my doctors office that said it is normal especially snice I had been on the pill for 9 years. She just said if it continues for a few more weeks then I should come in a see a doctor. My concern is that I still haven't started my cycle for this month. I knew it could Change timing of course now I'm not on the pill, but how long must I continue with these symptoms before I get it? Has anyone else went through the withdraws of the pill??..