UTIs during pregnancy are really common. Your doctor can prescribe antibiotics, but they are pretty easy to treat at home over several days. I get them pretty frequently even when I'm not pregnant.
Cut as much sugar and caffeine out of your diet as you can (no soda!) as this makes a UTI worse. Some people swear by cranberry juice or over-the-counter tablets made from cranberries. The juice does seem to help. Drink LOTS of water, enough that you have to pee often, to help flush things out of your body. For UTIs, I also take about 1/2 a teaspoon of baking soda by mouth mixed with a little water twice a day and notice a huge difference. It tastes terrible but seems to really make me feel better a lot faster; I just use a shot glass to get it down quick.
Go to your doc they can give you something to help with it