Welcome to the forum. Don't get too anxious, have patience. Haste is waste. It is nice to know that you are trying to get pregnant. Irregular periods
do cause miscalculation of dates. Weight gain is also not good for pregnancy
. Exercise, eat nutritious food and maintain your BMI. Do not take stress
, stay happy and positive, sleep well.
You should get a pregnancy test done with your early morning, mid stream urine( high in HCG). If the test is positive, fine , if not, don't worry.
Get clinically examined, get blood tests done ( routine ), get thyroid
tests done. Assessment of your hormones is a must. Get USG done to rule out ovarian cysts, fibroids, any pelvic diseases.
You should also get your partners semen analysis
done. This will help both of you to get treated and get positive results. Take care.