We argued when my girlfriend asked if she paid my credit card

My girlfriend had to buy something with my credit card last month, and I said okay. But despite the due date for the debt passing, there's still no movement. Now when I ask again, she says, 'You're being too pushy.' Other than a few small expenses, I'm not really spending much money. But this situation is starting to annoy me. Am I overreacting, or is this a problem, guys?