implantation dip?

Katlyne • Single Momma of 2💜 Annabella Desire’e Lee 👶🏻👑👸🏻🌈 12.04.17, 8lbs 5.5ozs. Edward Alekzander 👶🏻👑🤴🏻♥️ 02.06.19, 8lbs 12ozs.
So I became fertile on the 3rd-10th. On the 8th (CD 16) I got a very strong positive OPK, and on the 9th (CD 17) I had an ovulation dip in my temp that went below me coverline. A few days later on the 13th (CD 21) I had another dip in my temp that went below my cover line and since then it's only been rising. I took a pregnancy test yesterday but it came back negative. 
Side note, my period is supposed to start in about a week. 
Do y'all think it was an implantation dip?