23lbs so far at 34wks isn't bad at all.
You just seriously need to be careful.
Up your water intake. If you do have any water weight, drinking water constantly will flush it out.
You wouldn't be gaining 7lbs and keeping it if you weren't eating a lot.
Just watch your portion sizes. Its really important.
At first I thought it could be extreme eater weight, but it wouldn't stick on that long.
Drink lots of water.
Gaining too much weight during pregnancy can harm you and your baby. You can get diabetes and in turn pass it on to your baby. It can cause lots of complications during birth as well.
I'd suggest going on 20 minute walks. Up your water intake. Watch your sugars, calories, and carbs.
During pregnancy, you only need to eat an extra 300 cals. Less if you are over weight.
How far along are you?
Keep in mind during pregnancy, around 10-20lbs of the weight you gain alone should come from the baby, increased blood volume, amniotic fluid, increased breast size, thickness of uterus etc
When I was pregnant with my daughter, I gained 60lbs. After I gave birth (nearly immediately after) I lost 20lbs. That was from birth alone. So the extra 40lbs I packed on was completely unnecessary.
Sure, breast feeding could have helped burn some.of the fat. But that's the keyword. Some.