Implantation bleeding?

Wipe and saw a little reddish brown discharge on the tissue after urinating. Wiped again but theres nothing. We're ttc for 4 months now. I'm always regular and I'm one week to go before my AF. Notice 2 days of urinating early morning (around 2- 3am -not my usual routine), sore breast for 2 days now with more prominent montgromery tubercles too, and nausea today. Preg test was negative today. What do you think guys? Thanks! More baby dust!