BBT Drop early pregnancy?

Has anyone who has conceived and had a temp drop this big after positive hcg? It was darker than yesterday and showed instantly, sore boobs, back, nausea. I'm probably not gonna keep temping so I don't stress myself out. I think I only got 2.5 to 3 hours sleep last night so might have been that. I've also been told by a friend that low blood sugar or blood pressure can make a drop. Just curious as this is our first and my partner and I are over the moon.