Think you have two choices with HRT, either sequi or continuous.
Sequi is definitely the correct option if you are still having periods, albeit erratic because as you rightly mention, this will give you a reliable bleed each month and you will know when your periods naturally phase out.
Continuous is only suitable if you have been period free for at LEAST 12 months.
Bleeding on ANY new HRT regime within the first 6 months is pretty usual. After six months, it needs to be investigated. This is usually via a scan/biopsy. Mainly they are checking for the thickening of the womb lining.
I’m wondering whether you would be better taking the utrogestan sequentially rather than continuously, as you haven’t been period free for 12 months yet?
Also be aware, some HRT regimes can just make you bleed unfortunately, even when periods are over and done with for years! Sometimes there is a cause, e.g polyp, cyst, fibroids etc. Sometimes there is no direct cause.
For some women, utrogestan doesn’t keep the womb lining thin ( hence bleeding) and an alternative progesterone is required instead.
I wouldn’t worry unduly. If the bleeding persists or becomes problematic, then it will be time to chat to the GP I expect.