Trying To Conceive. FSH, Estradiol Normal, LH Surge Seen. Premature Menopause?

Hi . am a 34 year old female , with relatively regular periods [ 30 - 32 day ][ cycle . I have a son and am trying to conceive since the past one year . My day three FSH and Estradiol are normal [ 6.6 and 35 respectively ] LH surge is seen using ovulation strips . Mt cycles have now shortened to 26 days since the past two months . Am I heading for premature menopause due to poor ovarian reserve ? What tests do I need to do further ? thanks