Don’t know what the hell is happening 😩

Hey ladies!

Just wondering if any of you can offer some kind of advice.

My period was the 30th October to the 3rd November.

My fertile window was 4th-14th with ovulation taking place on the 11th.

I had brown mucusy discharge which changed colour to pink from the 14th to the 16th. During this time I was very tired, headachy and had awful lower back ache. I think this could be implantation bleeding! However I’ve done 3 tests over the last week and they’re all negative. Do you think this is implantation or just some strange discharge? My period was due today and it’s not arrived, negative test this morning too!

Has anyone experienced this before? Please help