Periods & Pain Sensitivity

It's just an off-hand remark with a non-period pic, but Dacia's started right before she got work done on her tattoo and she thinks that's very bad timing.

I seriously believe that in preparation for your period, your blood thins. I don't know if I've ever read that being the case or not, but before my period starts my nose starts getting bloody (I don't get bloody noses, my boogers just get blood in them) and my gums are more likely to bleed. Maybe an increased susceptibility to bruising goes along with that?

Any women who've noticed something like that or anyone who can provide links backing this up (or directly refuting it) please comment. I also wonder if Dacia bled more while she was being needled or if it just HURT more.