Hi Sharon,
It can take a few months to settle onto a bleed-free HRT like Premique.. this sounds like breakthrough spotting to me, but if you are worried, check with your GP or Nurse Practitioner (whoever's better with HRT).
Some ladies never really become 'period-free' on continuous combined HRTs and end up on cyclical HRT for their own peace of mind.
Hope this helps.
Galadriel x