Three days late cramping neg tests

Hi! I’m never late. But, I’m currently 3 days late I’ve taken 7 tests and they’re all negative. I’m having crazy cramps. When do I need to be concerned something is wrong? I’d assume there’s no chance of being pregnant. I’ve used two of the early responses tests.

I had an early miscarriage in February. My cycles have been fine since then. I’m not sure what’s going on and my OBGYN is not very helpful

Any experience or advice? Is this normal? Thanks!