I stopped drinking coffee as soon as I saw a positive. I had been off coffee for a couple years before (while TTC DD, pregnant with her and while BF). When I stopped BF DD in Jan, I slowly started drinking coffee again and was up a 1 cup a day. Because I knew I had done it before (and while working nightshifts at the time!), I wasn't that worried. I know I'll be back to drinking it again once I'm done BF this little one (in a couple years!)
Since I'm in graduate school and have a 1 year old who is not sleeping through the night, I'm having my morning coffee. 1 cup of half reg/half decaf. As soon as I can, I'll switch to just 1 cup of decaf a day. I often want an afternoon boost as well, but I've been doing fruit smoothies instead, which have been very helpful!
I stopped basically at week 4 because it began making me dizzy. I usually make french press at home and it is pretty strong but I was out of town and had a latte and was immediately like, "oh man this is no good" after I took the last delicious sip. Dizziness set in and I've avoided since. I have had the occasional sip of caffeinated tea or soda but I actually feel fine without my morning coffee which is a first for me since my teenage years! I might start back up after the first trimester if the dizziness it causes subsides.