Chemical? Or is this normal?

Im 4 weeks 5 days today. A few hours ago i had some slight cramping and felt a bit wet...when i checked, there was some brown/red blood. About the size of a small coin. After i wiped there was a little bit on the tissue also. Ive still got some cramps now but theyre not really painfull. They are not constant either, ive wiped a few times since (checking and wiping every 30 mins!) but no more so far 🤞🏼🙏🏻 am I worrying for nothing or should i be worried??