Need help girls

Can anyone give me advice🙈 (long post)

my period was due on the 18th of January and it still hasn’t came, I took 2 early detect tests on the 15th of January and had 2 faint positives but from then all I’ve had is negatives! I had one bit of spotting on the 19th which has never happened before and from then I have been getting very mild cramps, I’ve spoke to my doctor and she’s saying its sounding like a very early miscarriage (chemical pregnancy) but surely I would have started to bleed by now? My period is 15 days late tomorrow should I contact my doctor again??