I had an abortion 12mths ago. If I get a period it lasts from a few hrs to 1 day and is usually light. Although I suffer from polycyctic ovarian is this common? What blood tests can I do to check if something is wrong. I am also worried about my fertility

Anovulation? Your irregular and light periods probably have nothing to do with the abortion. They are probably from PCOS. Women with PCOS frequently don't ovulate. This results in irregular periods and makes it hard to get pregnant. If you want to get pregnant, you should be seen and have tests ordered to find out if you are ovulating or not. If not, there is medication to help you ovulate. Best wishes.