Pregnant and PCOS

hi ladies so I have some questions in regards to possibly being pregnant. I am currently a week late and I was diagnosed with pcos I have taken a few pregnancy tests and none of them have come up positive. I am just curious if you can still be pregnant and not test positive. I have read that when you have pcos then the hcg levels are lower and I have a few symptoms but nothing concrete I have a little discomfort in my lower stomach and I have felt a little nauseous and I have to go to the bathroom like every 5 min or at least have the urge to go all the time. if you guys could please let me know what you think I would really appreciate some insight. Thank you.