Hi,
Welcome to healthcare Magic!
Taking a tablet of
folic acid will not help get pregnant, this is given mainly to prevent neural tube defects in the early fetus so to prevent some of the birth anomalies.
If you are sexually active and periods are delayed then you should get a urine
pregnancy test to rule out pregnancy.
The periods, if habitually irregular then you should consult a local gynecologist.
You may be having a hormonal disorder like PCOS,
diabetes,
hypothyroidism, if you are obese weight reduction may help.
A sex hormone hormonal essay, thyroid profile, hemoglobbin levels, and
ultrasound of the abdomen are advisable for you.
I hope the advise would be informative and useful for you.
Take Care!