I want to know when is my ovulation I am 28days...

How to know ovulation days
ovulation time or the time ovum exist are the first 4 days of the last 16 days of the period , for example if your period is 28 days and if your first day of period was 1st/4  your ovulation time is
12th-16th /4 
and  the ovum last 48 hours in the uterus and can get fertilized any time during this period of time
and male semen lasts up to 5 days in female uterus and will be able to fertilize during this period of time , but the earlier the better
Medication to help you get pregnant
multivitamins and fertility supplements
ovulation activation injections
 folic acid
advise
- first , consult your doctor before taking any of those medication