Okay, so I literally started temping yesterday

I've read up on it and have my bbt. I should be 3dpo right now, and yesterday my temp was 97.89, and this morning was 97.70. Is that instantly a bad sign at this point in my cycle? I woke ip 15 mins later today than yesterday, could that make a difference?
Is it possible that I'm not getting the hang of it yet and the temps are wrong? I've been browsing the chart gallery on FF, and I don't see any charts, pg or not pg, that have one huge temp drop like that post O.