[Coffee.]

There's no difference between dollar store and name brand ones. Here's a scientific study, and I found many other sources on Google saying so as well. I would definitely take a pregnancy test, but also wouldn't worry so much; if you used a condom during sexual relations, so you weren't engaging in extremely risky sex, so this is likely just spotting. In the future, you maybe should consider another birth control method with condoms just so that you and your partner can be more at ease.