Testosterone levels VERY high

[c1991u]

Hello Everyone,
I'm wondering if anyone has experienced such a thing! I've been on hormones for what will soon be 6 years. I've always tested on the lower side on the range of 240-871 ng/dL  for total testosterone but yesterday tested >1,500. I was on injections for the first four years but switched to gel. My doseage has remained the same, I havent even felt off...I'm wondering if the test could possibly have been read incorrectly...but am anxiously awaiting some sort of explanatio n from my endo. I'm worried because this is dangerous if my levels are in fact what the most recent lab is claiming.
Anyway -- has anyone experienced this drastic increase in reading? Esp this late in having been on a stable dose for years? I'm not looking for medical advice, simply curious of other's experiences.
Thanks!

[Kylo]

For about six months my levels were crawling upward slowly, then around 7-8 months in they shot up to just above the male "limit" and no changes in dosage had happened during any of that time (was using gel).

As a counter I had to reduce dose, and have a battery of blood tests done which showed increase in blood thickness but not to danger level. No idea why there was a sudden rise in levels given that I've been using gel since day 1 without a break, but I guess these things happen.