Iintercourse the reason for irregular period?

I am kind of worried about my condition. I am 27 years old. Me and my husband we both wanted to have a baby. I had a miscarriage one and half years ago. Now we both wanted a baby badly. I always have my period regularly. Now this year on July we had intercourse several times sex for baby...but in September the period comes 8 days later...again we decided this month’s we will do protected sex..and the period comes in 30 days which was regular. Later this month’s we have been trying for baby for whole month....i had my last period on 12 of September .....now this months in October 21st today i have got my period again..i want to mention i had my regular period in September...i don’t know what to do..when I have done intercourse for whole month the period comes lately. And when I don’t do intercourse the period comes for regular basis. So now i m really worried...is there anybody who can help me regarding this matter.?