Consistent but light brown spotting?

Mandy

I'm about 5w2d now and have been having consistent but generally light-volume dark brown spotting over the past 5 days, for which my OB has given me progesterone that I'm taking everyday now. It gets slightly heavier when I exert myself like I take a 15-30 min walk or when I laugh too much. But so far it's never overwhelmed a single pantiliner, and most days it's usually just a few drops.

I keep reading that it could be cervical irritation but I haven't had sex in this period. Also implantation bleeds don't usually last this long and this far past my expected period, can it?

Has this happened to anyone and gone on to have a healthy pregnancy and baby? My first gynae visit isn't until next Friday and I'm so scared it might be a MC or an ectopic pregnancy (Google isn't helping!!)