You are TTC for last 2.5 yrs i.e suffering from Primary Infertility
.You have over wt/obesity also.
Need to investigate properly to rule out underlying pathology.Those are initial tests:
1) Fresh semen analysis
2) USG lower abdomen to check reproductive organs
3) Ovulation tests (you may predict ovulation by using ovulation kit as your period is regular)
4) Tubal patency test by HSG or laparoscopy
5) Rule out cervical factor if any
6) Hormone analysis like Thyroid profile,PPBS,Lipid profile
,LH/FSH and blood estrogen & Progesterone
So consult with your gynecologist and take advice according to your reports.
Do a Urine test for hcg after 1 wk of missed period to rule out pregnancy
. Do unprotected sex around ovulation time for highest possibility.
Control body wt by regular exercise to increase fertility,avoid salty and fatty food,avoid stress and take vit-E supplements with proper sleeping.