TTC, period due in 12 days and I'm in a lot of pain!

This is our second cycle trying to conceive. Husband travels a lot for work, so it's being very tricky to get the timing right. Seems we were right on cue this cycle though.

So, my period is supposedly due in 12 days, and I am in so much pain! Lower back pain and cramps/ovary pain. I am trying to remember if I normally get PMS symptoms this early. Also feeling bloated. I've looked online without much success, as early pregnancy symptoms can be the exact same as PMS, so no way of telling!

I don't want to test too early, as I have read that you can get a positive when the egg is fertilised (clinical pregnancy), but then if it doesn't attach to the uterus, which is apparently quite common, it would technically be a miscarriage. And to be honest, I don't much relish the idea of maybe getting a positive, to then maybe get a negative.

Two weeks is a bloody long time!!!