Hi.. my period last month starts on August 14 ends on August 20.then I started having period again this month September 11 ends at September 17.so when is the possibillities to get pregnant?how?

Chances are slim that you are pregnant since you had two regular periods. Are you trying to become pregnant?

It does not appear you are now pregnant.

If you are trying to get pregnant, you will want to properly track ovulation times, and plan intercourse, properly.

The way I'm reading your post, it sounds like you would like to know when your fertile days are. Sadly that's impossible to tell you. Do you know when you ovulate? Have you tracked your ovulation using basal temperature for at least 6 months? If not, then it's anyone's guess when you ovulate.

Good luck.

As Alty said, unless you are using various means to determine likely ovulation, you won't know for certain. Most women will, however, follow a fairly consistent pattern. This is why using the temping and charting, watching for changes in cervical mucus, and/or trying ovulation predictor tests can help you to narrow down when you are most likely to ovulate.

Generally, with regular cycles, ovulation will occur about 12-16 days prior to the next period... regardless of the length of your cycle. This gives you a starting place, but some women will naturally ovulate a bit sooner or later than this, and you can have an occasional off ovulation. However, with regular periods, ovulation tends to be pretty regular as well.

Having regular intercourse at least every 2-3 days throughout your cycles should cover the timing. Keep in mind that timing is only part of it, however. This is why it can take many months to become pregnant even when actively trying and knowing when you are most likely to ovulate. Most couples will become pregnant within a year of trying, but for some it can take longer even when all is well.