I drank wine at 3 to 4 weeks

We have been trying since feb of this year and I am happy to say I am pregnant - thing is I had a pregnancy test a week before my period was due and was negative so I had a large glass of red wine on my birthday.
​The next day I did another test on the day my period was due to find I was pregnant. 
​Aside from being cautiously happy (I miscarried in New Years last year) I  am worried about this stupid glass of wine I had.  I have definitely stopped drinking alcohol and caffeine. 
​Any comments to share? :(