Hia,
I know how you feel, my utro cycle started during xmas too :/
I wouldn't think of missing it as an option though and don't think you will going forward now either. Maybe it is to do with the change in the way you're taking it.
Even if I started a bleed on day 8 of Utro which happened a lot with me, the ppl here and the party line is to carry on until the 12 days are up for obvious reasons. Not sure there's much that can be done now, hang in there, feel better soon.
See what others say.