Does anyone know when they are About to get a blood clot? When I'm on my period I get an excruciating striking pain in my lower back and stomach for about a minute or 2. About 30 seconds after I know that if I push as if I'm about to pee, a blood  clot is coming out. This happens to me every time but I just can't seem to find any explanation for it. Everyone who I've asked about it tells me it's weird and that their clots are absolutely painless. Does anyone experience this pain before a huge blood clot ?