it seems like i can only taste pepsi is this normal during pregnancy
I'm not sure what you mean, but if you're referring to changing tastes, it's very normal during pregnancy. Many women find that what they previously liked or could tolerate became intolerable during the first trimester.
Though you didn't ask for nutritional advice, if you drink a lot of soda, you might want to consider cutting it out or reducing it during pregnancy. Lots of calories and no nutritional benefit. Just a thought.