Get your health thoroughly checked out before you start trying to conceive, even if you feel fine. A chlamydia infection may have no symptoms, for example, but it can lead to pregnancy complications [source: American Pregnancy Association]. Uncontrolled thyroid disease can lead to congestive heart failure, pre-eclampsia, premature birth, low birth weight, or even miscarriage or stillbirth [source: National Endocrine and Metabolic Diseases Information Service].
That isn't to say that women with hyper- or hypothyroidism can't have healthy pregnancy -- they can and do. It just means that extra care needs to be taken.
The same goes for women with diabetes. Poor blood sugar control, even in the very early weeks of pregnancy, ups the risk for birth defects and miscarriage [source: American Diabetes Association]. It's important to get your levels in your target range months before you try for a baby.
Go in for a full workup from your trusted doctor so you can both come up with a plan for getting in the best health.