Miscarriage or very early period

I'm desperate for some advice.

My husband & I have been TTC for about 15months. My periods are slightly irregular - between 24 - 29 day cycle. 

Today is day 12 of my current cycle & I've been expecting to ovulate but instead ive had what seems to be my period (quite heavy so I don't think it could be ovulation spotting ).

I've never had 2 periods so close together so I went to see the doctor this afternoon. He was quite matter of fact & said it could be an early miscarriage or an early period. As I'd not taken a period test in the last couple of weeks there was no way of knowing.

The whole experience has left me frustrated and very emotional. Has anyone else had similar experiences or any advice for me?

Thanks in advance.