I am now that I've read up on round ligament pain. Anatomy isn't my forte, especially physio, so I've had to play catch-up.
It sounds like the uterus is attached to the right side somehow (in some way) by the round ligament, and the pains/cramps sound exactly what I'm experiencing (and where). I was worried that I've got a luteal cyst or ectopic pregnancy, both of which can cause my chart and lack of positives, but I'm less worried now.
I know not even a strong positive can stop a potential chemical or miscarriage, so I'm just hoping that it's taking its time to dig in deep. ;-)