Hello
You are having irregular menstrual cycle . I want to tell you ,that irregular menstrual cycle don't causes
infertility . But the cause of infertility may be irregular cycle , if proper care in not taken.
You want to get pregnancy .
Cycle is irregular .
In my opinion you should do sexual intercourse on day 14th 15th of menstrual cycle because these are ( probable ) ovulation day .
Count day 1 when your menstrual cycle begin.
Get in an
ultrasound of both ovaries to rule out Poly Cystic
Ovarian Disease ( PCOD ) , as this is most common cause of irregular bleeding.
Also get in hormones examination for estrogen ,
progesterone ,
testosterone .
Since married for 6 months , so don't take any tension , mere coincidence that you did,'t get pregnancy .
Deal as mentioned above and you will get success. Still no pregnancy ( say 1-2 years ) then consult an INFERTILITY SPECIALIST and get his opinion.
Good luck.