Am I miscarrying?!

Currently 5 weeks 4 days. Had only mild symptoms so far - a few waves of nausea each day and some tiredness. Yesterday evening I started seeing some pink spotting. Not a lot, but this was accompanied by some mild aches. Today the spotting is brown and I still have the aches. It's very difficult to describe - not cramping, just a heavy achey feeling low down. After a mmc in December I'm absolutely petrified I'm having another miscarriage. I've called the EPU who won't see me until I'm 6 weeks. Hoping to get progesterone then but what's going on right now? Am I miscarrying?!