Advice needed please!!!

Hi everyone, so I just found out that I'm pregnant and my husband and I are super excited, we weren't planning because of a few hiccups in the marriage but after finding out, we're both over the moon. My concerns are as follows:
I took the test and it stated 3+ so I gather that I'm over 3 weeks but my issue is that 3 weeks ago I drank excessively however I'm not a drinker but celebrated my birthday for the first time in a very long time, then 2 weeks ago I donated blood, I also took flu medication. 
Do I have tons to worry about ?