You are 30/F, your husband is 50 yrs old a known DM, taking treatment. If there is no obvious problem, with all the conditions explained by you both are fit to have a baby.
If you really want to have a baby certain investigations are needed for both of you.
1) Your husband's semen analysis
2) A routine check up of your reproductive system like USG, basic blood and urine analysis and treatment of your menstruation
if it is irregular.
Get advise from a gynecologist about what is safe and danger period, and concentrate on the danger priod.