BBT: Did I ovulate?? UPDATED

Mackenzie
My husband and I have been TTC for 15 months now, but I just recently started tracking my BBT. I recently ovulated, but this morning my temp had dropped again. Doesn't that automatically mean I'm not pregnant, or could it still rise? 
UPDATE: continued charting to see if I ovulated. Still not sure what I'm looking for though? Is the temp increase a good sign of ovulation? 🤷🏻‍♀️