I weighed much more than you, but I'm also taller at 5'10". I had twins my first pregnancy. Since I was blessed with HG I actually lost 60lbs. I wasn't able to BF for more than a few weeks, so I didn't have any weight loss benefit. My doc with the twins was not very supportive of my weight and didn't have much concern over my weight loss. I ended up seeing one of her partners more and switched to him after the twins were born. I was the 'poster child' for gestational diabetes and increased blood pressure but I had neither, in fact my blood pressure was awesome my entire pregnancy.
With my second pregnancy I started at about the same weight. I had HG but it resolved some around 22 weeks so I did gain weight. This time I had a very supportive doc, who while she encouraged me and never made me feel bad, she was open and honest about the risks having a pregnancy would bring. Again, my BP stayed low and I didn't have any issues with diabetes. I was able to have a near natural VBAC and had no complication related to weight at all.
With M I BF'd for 2 years and actually pumped enough to donate and feed another baby. Again, no weight loss benefit for me
There are definite risks going into a pregnancy being obese...but if you are educated and know how to avoid, minimize and/or recognize them it shouldn't stop you from going forward.
Mommy to Twins plus One - donor 733