Periods issue. Or very less flow?

I have been fairly regular With my periods always. never faced any issue. but this the first time that i am already on my dates but my periods have not started yet. instead there was just spotting on day 1 and very less flow on day 2 with very dark and kind of thick blood and now is day 3.  this has never happened before. i feel bloated but no body pain like what usually happens before periods. Other symptoms that doctors usually ask for in case of any issue with menstrual cycle- Hairfall for the last 2 years No acne issue No weight gain or loss No unexpected hair growth like facial hair etc. Should i get some tests done or is it ok to skip period for a month with just spotting or very less flow? This has happened for the first ... Also, i have been sexually active but not for the last 5 months and i jad my normal periods in the last 5 months