Just refound my notes - So my highest level of FSH was 23 one month, however on the whole from day 3 bloods it ranged from 10 to 12.2. LH at 10.3. I was 32/33 around the time of the tests, with normal BMI.
Consultant was very keen that blood tests were done to include early period spotting not full onset. Done between 2 and 5 days. Plus progesterone at day 21 to confirm ovulation, which it did. They also pushed the healthy diet and weight piece heavily throughout all consultations... until she finally met face to face and could see I was not overweight!
Note that blood tests are only current for 6 months so they will retest you multiple times if needed so results are current.
Be careful what you read and action without seeking advice. Particularly around supplements and as others have said, don't get put off by what you read. As you will find IVF success rates are not great with elevated FSH so potentially not funded on NHS, however our NHS Trust/consultant were happy to do one round. It is such a individual postcode lottery and can be disheartening to read /hear but keep pushing .
Separately, we started using the clearblue digital ovulation monitor (the fancy, expensive one) in the 3 months prior to conceiving. It is expensive, but it helped reduce the pressure, stress and unknown for us.
I hope this brain dump helps a little and good luck with your appointments.