A little concerned

Sam • Mum of a 2yr old daughter, recovering from a complete molar pregnancy, Adoring fiancé, looking forward to TTC again
So I'll cut my long story short- I had a d&c on December 2nd due to a complete molar pregnancy, 
My period came on the 18th feb, 
Before my d&c I was a regular 28day cycle, 
So far my period for March hasnt shown, I'm nearly a week late, I did a test yesterday and it came back negative, 
We haven't been trying for a baby yet as we aren't cleared to do so, but in saying that we have only been doing the pull out method, 
How long does it take for your period to regulate again? Is this normal to happen? I'm going to test again in a few days just incase, 
I'm concerned I will be pregnant only because  I have had a few glasses of wine this week, would it be ok?