Tmi period in between period :/

Really new to this so just wanted a bit of advice. Been ttc for nearly 6 months now. Trying every 2/3 days but becoming pretty difficult when I'm having pretty much a week or two before I start to heavy bleed again. I've been to the docs and they just put it down to irregular periods. I've suffered from heavy periods for years and I have a 3 yo daughter so I know I can get pregnant and have a healthy pregnancy. I'm just wondering if there are any ladies out there who might be experiencing bleeding in between periods and finding it frustrating when you can't really try whilst you are bleeding :( sorry for the long post. Any helpful advice welcome