So get a calendar, and app, or a tracker and bring in the last 3-6 months of your menstrual cycle. Confirm with your gyno when to have sex
Normalize your weight (as much as possible) and boost your nutrition, this is a time for basic vitamin use, pregnancy vitamin guidelines can be found on line
When you track your cycles, you need to know if they were ovulating, figure out if you are ovulating, simple tests are available in the drug store or with free apps, fertility problems respond best to early treatment so if the tests aren't positive, come in to your gyno to discuss!
Treat all vitamin deficiencies. get iron in your diet to improve your iron stores, begin folic acid and begin Vitamin D if you have blood level deficiency, and this is a time of your life you may have to consider eating meat if you are vegetarian, read ACOG nutrition recommendations
Take omega-3s, or eat more fish (check locally regarding fish mercury recommendations)
Track your blood pressure, blood sugar, and your BMI, get any hypertension, diabetes, obesity (ideally) get these treated before conceiving, it will lower your miscarriage and birth defect rate
Treat any vaginal or bladder infections, discharge and odor, see your gyno if you have questions
Decrease toxin exposure, minimizing red meet can also reduce hormone exposure, toxins can be found in unregulated supplements, always check with your health care provider for questions
Get a visit and perhaps blood testing to confirm vaccinations still are current, and catch up on vaccines prior to pregnancy as some cannot be given when you are pregnant
Get tested for Herpes if symptoms are suspicious, and get on suppression medication if your gyno thinks it is indicated
Ask your family and his family about any known genetic problems, and get blood genetic testing for you and the baby's dad; there are so many options, consultation can lead you to many sources of information, it is not legal to be discriminated against on the basis of genetic information, so that is not a reason to not test
Exercise regularly, and take up swimming and yoga which can be carried as your exercise all through pregnancy
Drag the baby daddy in and get any problems with him sorted, his health will impact fertility, miscarriage rate, birth defects, and stress levels
Make time for sex!
Get a good home pregnancy test, there are some that turn positive before the missed period and estimate how far pregnant you are