The hCG pregnancy hormone doubles and redoubles every few days. If the faint positive was the most recent, another a week later would be a good idea. Make sure to read the test at the specified time limit, then throw it away.
There is a long list of possible early pregnancy signs. Fatigue, weird cramps, changes to appetite, emotions, breasts, nips, peeing, backache, headache, acne and more. You mention so few that I doubt you are pregnant. You don't say what kind of sexual exposure you had, or if it was in the fertile window. Buy your own condoms for the next adventure, and insist on their proper use. Best of luck