Pregnant or just medicine?

So I started on metformin (to lose weight) and at the beginning I felt so nauseous because I didn't really eat anything with it. And today I took it with food and I've been fine all day. But now I feel nauseous and I've been going to the bathroom more. My husband and I are currently ttc. Not sure if the medicine is just messing with me or should I take a hpt? It's been a little over a month since I've tested.