-What happens during extended period?
-Should we be worried about pregnancy?

My SO has irregular periods. Sometimes these last 3 months, 2 weeks or maybe a couple days. Time between periods are usually 3-6 months. She and I had unprotected sex because I figured it would be safe since it was 2 weeks into the period. Then her period ends the next day. This raises some flags, but we figured it'd be ok.

5 days later, crazy romantic night. We didn't think about what we were doing and had unprotected sex again. On a normal chart, this would be the most fertile time. But since it was an extended period, I'm not too sure. what exactly happens during extended periods? I can't find any information about it, just sites to cure it.

A day later, she starts getting a stomach ache, and starts bleeding again. Now she has cramps and is bleeding again (a day after).

Should we be worried about pregnancy?