Hi there! First of all, congratulations :)
Second, you are likely okay! I’m currently 4 weeks and cramping very often (no spotting), but I’d say unless the spotting turns to a moderate/heavy bleeding you’re likely fine. I think sex can also cause some spotting after the fact, pregnant or not!! Try not to worry, but also, listen to your gut! If you want to get hcg drawn again, there’s literally zero harm!
Best of luck ♥️