this question seems to come up routinely since i've been on these forums and i always give the same response
i usually drink wine with dinner (one or two small glasses), and i have one coffee and one green tea a day. i conceived my first 2 kids without even trying, and without changing my habits. i continued to drink my one coffee, but cut out alcohol completely during my pregnancies, both of which were easy, healthy & full-term (with healthy, normal-weight babies at the end).
now that i'm actively TTC for the first time ever, i've cut back a little on wine, but only in the 2WW. no change in my coffee/tea consumption.
my reasoning is that if these things didn't prevent me from conceiving (even too easily) the first two times, it won't be those that prevent it this time. both DH and i are older (DH is considerably
older -- well into his 50s), so if the TTC doesn't work, that will probably be the reason. our attitude is that we're trying to enjoy the process, and i certainly don't want to cut out the few things that bring me great pleasure.
i have a very healthy lifestyle in terms of food, sleep & exercise, so i feel that i "compensate" in other ways. but i sincerely feel that coffee (which i drink black & unsweetened) and red wine also have health benefits...