Hi. I’m new here..need some advice.

My period was due last week, instead I got brown discharge from Monday evening with about 4 hours bleeding on Tuesday (this is SO graphic- I’m sorry)..and then back to discharge. It stopped on Friday evening. Could it be implantation or am I getting my hopes up for no reason? I do feel nauseous, have constant cramping and headache is killing me. I took a test on Thursday which was negative. So I decided to wait until Sunday next week to make extra sure enough time pass.

Would really appreciate some advice on what to expect.