WHAT IS MY BODY DOING?!?!

I am fairly new to the glow community, I don't know all of the abbreviations that are used so sorry if this turns into a long read.

My periods last anywhere from 4 to 6 days, usually right on time. This cycle I got spotting 5 days before period was due and it lasted 3 days, 12 days after ovulation. Day one of spotting I used a tampon because when I felt it arrive it felt like a potential flood(tmi, my bad). I got to the bathroom before I thought it was going to get crazy and when I went to get myself cleaned up there wasn't much a little red but mostly brown. Changed it 3 hours later and there was brown/red blood, and not a lot so I changed to panty liners until further notice...

Further notice never came(yet) and here I am, wondering what on gods green earth is going on 😂 the last 3 days I have had headaches galore(I drink 5 bigger bottles of water a day, so not dehydrated) I feel nauseous like crazy, COFFEE of all things made me gag this morning 😢 mild cramping night one of spotting with little twinges here and there, tender ta-ta's and back pain. Maybe I am jumping the gun and just had a weird period, I don't know. Going to give it a few days then take another test. Period was due today but no sign of her rearing her ugly head yet, took a test this morning and was negative. I thought I saw a vvvvfl but not entirely sure.

I am engaged, have 2 littles already and we do want a third.