On minipill for endometriosis no periods for about a year and had one last month half way through pack just started new pack and period again. normal?

Normal: The so-called "mini-pill" is a progesterone only pill. Its doesn't give you regular periods; however, most women do occasionally bleed while on this pill. With a regular birth-control pill that has estrogen and progesterone in it, your period is supposed start during the 4th week but with the mini-pill it can happen randomly any time. Best wishes!