Confused Muffin Here

So...I am currently six days late on my period...happened last month however it came after day five of being late. However that wasn’t much blood at all.

I am confused.

I take birth control. I wasn’t able to get my meds for a month and got them back. I’ve been taking them for three months now and idk if it’s messing me up because it’s like a restart to the meds or what.

And I know birth control isn’t 100%, and that even when having sex, there is a chance of something happening.

I’m just not sure if I should test or wait or if it’s just me readjusting to my meds. Any advice?

*UPDATE*

I have started to feel slight cramping and back pain. I have also noticed some blood but it seems more like spotting rather than the usual flow.