Can anybody make any sense of this?

well i hav been TTC for 9mths now, through home insemination. and i hav invested in a first response ovulation monitor, my cycles hav been slightly irregular.... btween 25 and 28 days, so ovulation is varied. well i was due AF on 17th march, but had slight bleedin on the sat which stopped by the dinnertime, i came on fully on the monday.... which date should i go from???? my monitor was flashin alternate babies this morn so i took OPK and there was a slight line on it does this mean im gonna ovulate early or am just seein to much into it???? answers on a postcard please ladies and congrats too anyone who gets their BFP this mornin xx