It increases the risk of miscarriage a little if you drink it in high amounts. You can still drink up to 200mg/day (some places recommend up to 300mg/day, but I prefer aiming for a smaller number just in case). Starbucks, if you go into the store and order a regular coffee, is probably around the same as a normal cup of coffee and you can have a few cups, but their mochas and such have a lot more. One mocha is probably already at the max (I know the small mochas at Caribou Coffee already have 190mg, I have to order mine with half the amount of espresso -- and I pretty much only get it once or twice a month, as a treat). However, if you get the bottles of frappuccinos, those are each under 90mg, some as low as 60 I think. If you google the specific drink + 'caffeine content', there will be a web site that tells you what it is. So you don't have to quit drinking coffee, just be careful how much you do drink. Personally, I found that it just didn't go down as well once morning sickness hit, so I haven't had any in several weeks now...
Starbucks does list caffeine content of different drinks online. If you stick to tall size or only one espresso shot you should be OK.
Mocha will obviously be more bc of chocolate.