What are the chances of pregnancy if the condom slipped off is still stuck inside?

There's a very similar question on Microgynon usage, and chances of pregnancy here. Essentially, you are protected from getting pregnant after 7 days of consistent use of birth control pills. Consistent usage means that you’re taking the pill every day. If taken correctly, Microgynon protects against pregnancy 99% of the time. This means that less than 1 of 100 women will get pregnant with perfect use of the pill.

If you suspect there is a high chance of pregnancy, I would suggest repeating the urine pregnancy test in a week’s time. If it still negative then it is unlikely you are pregnant. Irregular bleeding like what you describe is not uncommon in PCOS even in the absence of pregnancy. I would recommend using contraception if you are sexually active. In addition to preventing pregnancy, contraception like the oral contraceptive pill (OCP) will make your periods regular and light, and prevent endometrial hyperplasia (build up of womb lining) which is very common in PCOS.