Irregular period

Anyone over 40 have irregular period. Waiting to be seen by dr. I’m 41.5 My cycle was usually 24/25 days then I did <a href="https://glowing.com/glow-fertility-program">ivf</a> that turned <a href="https://glowing.com/glow-fertility-program">iui</a>, had a chemical and last two periods were 21 days! Now I’m only cd26 and no period - what can this be? Premenopause?