Insight?! Anyone?!

Well. Super out of character and weird for me but I’m hoping someone has some insight. I last BD with my boyfriend March 20-24. He works out of town right now so we have to stay busy during our time together LOL. I had actually JUST ended AF the 19th of March. Yesterday, with no warning, I had light bloody spotting for about 3-4 hours later in the day and since, nothing with it kind of tapering off to a light brown before it stopped all together. I am 3 days into my high fertile/ovulation week according to my calendar with Tuesday being my highest day. I am not due to start AF again until April 17th. Nothing like this has ever happened to me before where I’ve had spotting like this for a day. My periods have been regular with being every 28-29 days since I’ve been off the pill for a year now. Could this be implantation bleeding even though it wasn’t my suspected ovulation time when we last BD? Kinda confused..I don’t know what else to chalk it up to since I am still 2 weeks out for AF to actually start?!

Thank you in advance!