Ovulation and periods 😕

Me and my BF had sex on the 7th of this month and on the 10th. My fertility days are from the 8th-14th. For the past few days I've been nauseous and extremely tired. I even missed work 2 days because I couldn't get out of bed. My cycle was 2 days late, but this morning I have spotting and it's light in color and odorless. Should I assume that this is my cycle and it just came late, or should I wait a few days and then take a pregnancy test? I've been tracking my ovulation and cycle for almost 5 months and I still can't seem to get pregnant. What am I doing wrong?! 😔