Of course! Please bear in mind that what I'm posting is medical guidance and not opinion.
Your agreement to swap to a new form of HRT should always be discussed with reasons given with the pros and cons so you are actively involved in the decision.
You've been swapped from a (safer) body-identical type to a synthetic type of progesterone with no explanation (from what you've said.)
The previous 25 days on Utrogestan is a bit outdated but maybe your GP wasn't aware? The 'risk' of 25 days is that it allows a 'window' for a bleed which may happen as it's not being taken every day.
https://www.menopausematters.co.uk/postmeno.php
UTROGESTAN
Micronised progesterone
100mg at bedtime from day 1 to 25 of each 28 day cycle (licensed regimen), though taken every day is usually recommended
I wonder why you've been advised to halve a patch. Swapping doses within the week is more likely to give side effects as your estrogen and progesterone levels will be varying. It's the same as if someone was told to use 2 pumps of gel for 4 days and 1 pump for 3 days (and reduce the Utrogestan on those days as well.) On the days of 1 pump they may find flushes , sweats or mood changes occur.
Here is the link from the BMS guidance. The points I made earlier were about adding more Utrogestan if there is spotting or bleeding.
https://thebms.org.uk/wp-content/uploads/2021/10/14-BMS-TfC-Progestogens-and-endometrial-protection-01H.pdf
Page 3
The dose of the progestogen should be proportionate to the dose of estrogen. While no data is currently available on the endometrial effects of high doses of estrogen and the optimal dose of oral or vaginal progestogen in this context, women who require high dose estrogen intake should consider having their progestogen dose increased to ensure adequate endometrial protection (e.g. micronised progesterone 300 mg for 12 days a month instead of 200 mg in cyclical HRT regimens or 200 mg daily on a continuous basis instead of 100 mg in continuous combined HRT regimens).
This applies mainly to women on high doses like a 75 or 100 mcg patch.
Page 6
For the majority of women with unscheduled bleeding on HRT, modifying progestogen intake often controls the bleeding especially in women who experience unscheduled bleeding in the first few months after commencing HRT.
Progestogen intake could be modified as follows:
For cyclical HRT regimens, the dose of progestogen could be increased (e.g. micronised progesterone 300 mg for 12 days a month instead of 200 mg, or switch to a different progestogen) or increase duration of progestogen intake (can take progestogen for 14 days a month or for 21 days out of a 28- day HRT intake cycle).
For continuous combined HRT regimens, the dose of progestogen could be increased (e.g. increase micronised progesterone daily dose from 100 mg to 200 mg daily on continuous basis, or switch to a different progestogen), particularly when combined with higher dose estrogenic regimens.
If breakthrough bleeding occurs following the switch to continuous combined HRT and does not settle after three to six months, then the woman can be switched back to a sequential regimen for at least another year.
Sorry this is so long but it's important you have the info if you're going to query it.
Are you happy about dropping Utrogestan for the Norethisterone in the patch?
What were the reasons for suggesting that?
What was shown on the scan? Was it endometrial proliferation but regular/ benign and not a problem?
And are you having night sweats because your dose is changing mid-week?