Pregnancy scare, implantation heart rate rate

[Em2122]

I'm about 5 days after doing the deed and woken up with a rapid heart rate 102 bpm. I don't want to be pregnancy but remember my firstl pregnancy symptom with my 2 kids being really fast heart, though i didn't think it would be this early? Period not due for at least 4 days.
Do you think this could be Implantation?

I think it could be anxiety.

Does seem bit early to implant, but now I've had pains in my right ovary, making me more worried.