Why am I still trying to convince myself about this cycle?!

Sooo this is only my first month TTC so still learning. However I got what looked like a faint positive result on clearblue on the 11th this month. Everything since has been negative. I had some spotting start on the 16th and figured my period arriving but only had 2 days of red blood but not at all heavy - not enough to fill pad or tampon, no clots, no cramps (not a 'usual' period essentially) . I found out I was pregnant with my first child at about 8 weeks after seemingly having a normal period the month before so I'm all stuck in my head that I could be having implantation bleeding again but all tests since 11th still BFN. Is it at all possible maybe I could have ovulated later than app predicted or am I completely out amd wasting my time testing more this month? Ive bought ovulation tests today as I need more certainty my litle control freak brain cannot deal with second guessing the math!