My BMI is 32 and it's been me that's raised it at appointments, not dr/midwife - no one has acted as if it's a problem. I do merrily (well, trying to stave off humiliation) say I'm obese, though, so they know I know, because I just didn't look it and in the past I've had problems with people acting all surprised when they weigh me, when I know darn well how big I am.(feeling blimp like at 19 weeks, mind).
At my 16 week midwife appt I asked about it, and about diet and safe wieght gain, and she said not to worry, to try to eat healthily but not to diet or worry about the odd slice of cake, and that the amount of weight I gained wasn't really down to me. She told me a woman with a BMI of 80 had recently given birth in the area and she and baby were fine, and that although I was weighed at my booking appointment I wouldn't be weighed again and she didn't recommend me weighing myself (until I got PG was doing Weightwatchers so weighing myself weekly and had lost 3 stone).
The other thing I got really, really paranoid about was my tum getting in the way at scans/getting bad or unclear scan because I'm big. I had perfect, crystal clear scans at 11 and 13 weeks (date confusion meant I got 2) and the sonographer said I was easy to scan.
I'd expected to be treated like I'm naughty and/or stupid, and for everything to be much more difficult because I had got pregnant more quickly than I expected and hadn't lost the extra half stone, but this just hasn't happened.
Very, very long post, but hope it helps you not feel as paranoid as I did!