Ovulating whilst on my period?

M
So... Normally I ovulate on CD11-CD14. This month... Period came a bit earlier than usual but lasted for 7 days.. On CD8 i took an ovulation test and What!!!! It was +ve!!! We had sex that day and the day after. The day after tho... The ovulation test was -ve... I find it really odd that I ovulated that early... I wasn't ready lol !... Does that mean that I have to wait another month? Thanks xxx