My periods have always been on time since I had my son 14 months ago, but this month it was 5 days late and when I started I wasn't bleeding near as heavy as I normally do, I am also having lower back pain, really bad headaches, nausa, stomach pains and side pains, I don't know what could cause this, because it has never happened before.. Any advice

Have you started or changed birth control lately? Were or are you breast feeding?

No I'm not on any form of birth control, and I couldn't breast feed my son because I was on chemo after he was born and my mild supply never came on

You might want to check in with your doctor. I just thought it could be from changes I listed. Im sorry you don't feel good.