9DPO temp spike?

So this is my first month temping. About 2 weeks ago I ran a fever due to illness so I could not check and get accurate results for about a week. I usually run an average in the 97’s but this morning at 9DPO I got a waking temp of 99.92. I’ve been well for over a week so this is definitely not sickness related. Could this be a sign of implantation? I’ve read where it could be but also could be a normal sign of period coming.