Kazzie, I've just read up on your medication and that is a very low dose of oestrogen and a high dose of progestin which might explain your problem. Unfortunately, synthetic progestins cause low mood and breast pain and they also suppress the oestrogen content of the medication making it less effective at relieving symptoms. Also, that volume of progestin will probably keep the womb lining super thin which means that any slight build up will shed very quickly which has its benefits but also causes the bleeding problems you have been having.
Continuous combined HRT does have its merits in that you do not generally have periods but having tried a few myself, I think they are not for everybody and not always the best form of HRT. Depending on how you feel about having periods again, you might want to think about changing to a separate transdermal oestrogen (gel or patch) and progesterone (bio identical Utrogestan) which would have fewer side effects and offer better symptom control.
There are many women who are happy with continuous combined HRT and do not have any adverse reaction to it but if you do, perhaps it is time to think about a change.