Antibiotics and late period

Ok so recently I had a cold with a bad cough so the DR put me on antibiotics to clear my chest up. I started to take them for 2 days but didn’t feel any better so went back to the DR. This time was a different DR and he asked me to do a urine test just to check on a few other things. He said you have a UTI so put me on more antibiotics. I ended up with thrush from the tablets. All is cleared up now but I was meant to start my period within this time but it didn’t start. I’m currently 11 days late. I took a test at 7 days but BFN. I have PCOS so I thought maybe my HCG levels were too low because of PCOS but my question is could it be from the antibiotics. I feel fine now but my body still hasn’t returned my period. I used to be regular each month as well. What do you think ? I hope I’m pregnant 🤰🤞