Light brown when i wiped now nothing

Hi guys, ttc here. My last period was 9/15-25 (from light spotting to when i didnt have to wear a pad anymore) and i havent had any spotting or bleeding since then. I got checked by my doctor before that & she said my ovaries & blood are perfect. She said some women are just irregular. 2 days ago i saw light brown & a tiny and i mean tiny red/pinkish dot after i wiped, just that once.

Today i went candle shopping & all of the candle sniffing gave me the biggest headache. Then i got a quick somewhat nauseous (just the build up of saliva part) feeling but it quickly went away, i think its bcuz i was hungry tho. My nipples (not my boobs) have been sensitive lately. Ive ben having a big appetite lately too. Hoping it was implantation bleeding! I took a test 2 weeks ago & it was neg. Guna try another this week. Good luck ladies!