Implantation bleeding?

I need some input. I came off the pill Jan 21st after 10 years, but was regular before then, so glow estimated AF to come Feb 15th. Early last week I started having tender nipples and nausea on and off. I tested on the 17th and it was negative. Today I woke up and had some cramping then had wiped some darker red/brownish this morning but nothing on was on my underwear. Do y'all think it may be implantation bleeding?