I've have not been tested for pregnenolone, but I find low doses of pregnenolone (about 5 to 10 mg daily) strengthen the mind slightly, perhaps making me a little more resilient to stress.
If I take higher doses of say 50 mg daily then I notice I start to become a little aggressive (which I do not like). This is I think because pregnenolone converts to DHEA, and DHEA is known to increase aggression levels. SO this is why I use a low dose of pregnenolone.
Never tested it myself. However, https://app.labtestanalyzer.com has the following entry for high pregnenolone (always check their references, to see if applicable)
Higher pregnenolone levels may be a sign that your body is having problems converting it into secondary sex hormones (such as testosterone, estrogen, and progesterone). This can cause problems with sexual function or development [R].