Help!!! Normal?? Not Normal??

Warning: Long post ahead

I have pretty normal periods. They always come same time of month and all the 'normal' stuff happens. 2-3 days before I get mild cramps and backache and my boob's start getting sore. Normally my first day is miserable and I lose quite a bit of lining....I also bleed a lot - like super heavy. The next 4 days are not so bad and get lighter with each day.

There is the rare occasion that I skip a period but that happens like once a year if at all.

So here's where I need help.

My hubs and I have been having A lot more sex because we are trying. I got my period this morning but I am 9 days.....9 days early. That's NEVER happened!!! I had cramps and the backache but no sore boobs. This period is weird.......I'm hardly bleeding (more than spotting - like medium) and I've lost 1/3 of the amount of lining I usually lose....and it's the end of the 1st day and I'm barely bleeding....like at all.

I've never, in the last Ohhh 16 years??? - ever had a period like this. Can anyone shed some light on this??