New to Glow TTC need some help!

Hey guys, I need some advice I have had lots of trouble with contraception over the past few years cyts bleeding pains etc so my partner and I have decided enough is enough and start ttc which is very exciting! I had the mirena removed in January 2015 and since then my periods have been extremely heavy and coming every 21 days with massive pains nearly unbearable. Is this my body adjusting and getting all my levels back to normal im really starting to get worried. I need some advice

Thank

Larissa xxx