Hey, don't despair!
So firstly, when your GP put you on 25 days on and 5 days off utrogestan, that was actually a continuous regime. I know it had 5 days off, but the 'old' continuous regime had 5 days off - then they realised that actually this caused bleeding and you didn't really want women on continuous to bleed. So they changed it to be 100mg every night. So, if your GP is still using an old-style continuous regime, it suggests to me that maybe they don't know loads about HRT... The continuous regime (either of them!) is supposed to be for post-menopausal women, not peri. If you are not post-menopausal and they put you on a continuous regime, again, it suggests they don't know loads about HRT.
In putting you on 200mg for 2 weeks and then stopping, that is the sequential regime. It is for women in peri-menopause who are still expecting to bleed at some point and need to schedule the bleed. When you stop the progesterone, you will bleed.
I haven't heard of either being associated with lighter bleeding. But if you are expecting to bleed, you wouldn't be on a continuous in the first place because you would just get unpredictable breakthrough bleeding.
Finally, the Mirena coil is one to consider. It is a very low dose of progesterone and not much of it gets into your system, compared with a progestin pill. (They have measured serum blood levels of the progestin in women on it.) Fibroids are known to cause nuisance bleeding and the Mirena coil is known to really help with that. If you don't get on with it and have progestin side effects, you can get it removed - don't forget that it's your body and you can request that
After 6 months on the Mirena, most women stop bleeding altogether. And it lasts 5 years. So most women who try it, love it.
Otherwise, utrogestan is not always the best option for problematic bleeding but there might be ways to use it that would help - you would need to be working with a very knowledgeable menopause specialist GP though. For eg, I am peri (44yo) and I am on 200mg continuously - and (as of yet) not bleeding at all. I'm on that dose to suppress my endo. 100mg didn't work for that purpose, continuously. But so far 200mg seems to be. So you could increase the utrogestan. And if you then got breakthrough bleeding, you might be able to schedule it with the 25 days on and 5 days off approach - with lighter bleeding because you'd been taking a higher dose of the progesterone. Or you might be able to have a break every 3 months to schedule a bleed - that used to be a regime which has gone out of use as well, but was safe.