Hi Waterdaggers
It is obviously different for everyone although there will be some similar patterns. I am just at the end of my 12 ( well actually it's gonna be 14 days because of the 2 x 100 mg taken at the beginning and end) day cycle. As I mentioned the first 3 days this time I woke with a headache and stiff neck and thought I was getting a migraine - but fortunately each time it cleared (took an ibuprofen to help it on its way). I have to work too - but nothing that could cause anyone danger if I'm not quite 100 % - but have to stand up in front of groups of people and be on the ball and enthusiastic - delivering a type of training. Hopefully you will also get used to it. I am amazed at how I have got used to it this time. Sometimes my head gets foggier as the days go on but this time - I do feel very tired in the mornings (even more than usual) but my head is not foggy! Hallelujah!!! Plenty of caffeine helps I think.
Absolutely do not miss a day! You could feel worse the next morning as the progesterone withdrawal symptoms could kick in and make you feel very pmt-ish. Also it is very likely to trigger a bleed.
The progesterone changes the structure of the lining that has built up from the oestrogen (to get ready for a pregnancy) and when the level drops, your body thinks - there is no fertilisation so don't need this lining any more, and away it comes as a bleed. if you only miss one day - then this does depend on how thick the lining is and how long you've been taking the prog - but is quite likely to happen randomly! Once you've started the prog - do try to finish the course. All the time you are taking it as well - it is stopping the lining from growing again under the influence of the oestrogen you are still taking.
Make sure you eat properly and don't go hungry - especially don't eat too many empty carbs like sugary foods (sweets, sweet drinks, biscuits, cakes etc) - either slow release carbs and/or lots of protein - so you don't get jittery due to blood sugar fluctuations.
I am sure you will feel better after a few days - hopefully anyway - let us know!
Did you say you were post-meno? If so you might be able to stretch the cycle a bit...
Hurdity x