HI...
I am one of those people that use to drink tea all day. When i fell pg i stopped totally and suffered really bad headache and just couldnt get my energy levels up (or so it seemed) I went back to drinking 2-4 cups of tea a day (less caffine than coffee) and dont feel too bad about it.
Checked with my OB and he told me that it was fine.
Its the one think that i really enjoy that i cant give up.

Try not to beat yourself up, most of us will enevitably eating or drinking something that we shouldnt at some stage throughout the 9mths+ as long as you are trying to do the right thing the majority of the time im sure you will be fine.

BTW i had a friend that drank 600ml coke EVERY day and tea and coffee throughout both pg and babies were fine - i wouldnt do it, but some do!