My period this month started june 15 what is the best day of intercourse to make me 100% pregnant? thank you in advance.

Conception timing: If you call the first day of your period day#1, most women ovulate on day#14. This is when you are most "fertile". You should: 1. Track your cycles 2. Have intercourse on days 10/12/14/16 3. Abstain from intercourse before then 4. Consider using an over the counter ovulation kit. Your chance of conceiving in any one cycle is only about 20%. It might take 6-12 months to get pregnant!

Ovulation: As of the writing of this response it is mid august, so i assume you would have had a period in july and probably in august if you are on a 28 day cycle. Your best chance to get pregnant is in the middle of the cycle - day 13-16 of your cycle staring with the first day of your period.