50 day cycle?

I went to the obgyn a few weeks ago she said it’s nothing to worry about but it’s freaking me out. My period was only 2 days last month and my cycle was 45 days. My cycle is usually around 35-45 days. This month I’m going on 50 days. My boyfriend pulls out and I took a test a few days ago and it was negative. I’ve been kinda gassy and a little pukey but not a whole lot comes out. I haven’t been actually diagnosed with PCOS but I’m beginning to think I have it. My mom had it when she was younger as well. Is there any chance the pregnancy test was wrong and I am pregnant? Or do y’all think it’s probably pcos?