You can use Fertility Friend to chart.
http://www.fertilityfriend.com
You need a digital thermometer - just enter your temps each morn as you wake up - about same time and FF will help you out.
You can buy cheap OPK strips on the internet - buy loads since you are irregular. Buy about 100 - LOL. And test twice daily if poss.
BD very often as well. But not every day

they saythat weakens the sperm count.