Triphasic chart

Hello! 😊 pardon my english!

I have never done this bbt charting before, and I need your opinion. Yesterday my chart jumped, and got a little higher today as well. Its been a week since I ovulated, and I was thinking that this might be the egg that attatches itself? Or is it random? I’ve read that some people got this 3rd level on their charts when they were pregnant, and others got it even though they weren’t pregnant.

Please help me understand this 😅