HELP! 4 weeks and bleeding‼️😫

Hi, I got my BFP on FR digital about a week ago & I’m 4w 1d pregnant. Friday, I noticed that I had minimal spotting but nothing alarming. Then nothing to declare on Saturday except my period was due on that same day. Flash forward to this morning... I started bleeding very similar to a period: bright red & as heavy as normal first day of cycle but it didn’t last (one wipe and then it was over). I did have cramps in lower back and abdomen which were uncomfortable but not painful. I didn't see any clots.

I kept monitoring my temperature for a couple of hours and everything seemed fine. I’ve been having pregnancy rhinitis, sore nipples and tiredness but that’s about it!

With my first pregnancy, I did get my period for two months before I Iearned that I was expecting...my son will soon turn four. However, it doesn’t stop me from being worried this time around. I’m scared that I could’ve had a miscarriage . What does a chemical pregnancy look like? For those who did have similar experiences, how did it turn out? Should I be worried?