Welcome to HCM.
You have protected sex on infertile days. So there is no chance of pregnancy
.Don't be much worried.
Also you got normal period. Practice always safe sex
Heavy period in one cycle is not significant until it happens in every cycle. It may be due to hormonal
imbalance or uterine pathology.
So if you got heavy period in every month,then do a USG scan for pelvis and consult with gynecologist.