Shortening Cycles & Fertility: Understanding Conception Challenges

Question
Hello. I saw very similar post from someone else and wanted to know if my case if same as hers. I'm 31 and have been married for 1.5 years.  I've been with my husband for 11 years and had 2 abortions(both by him) back when I was 20 and also 21. I was on the pill for 6 months when I was 20 but got off and haven't been using anything since. We have been trying to conceive since last October but haven't been successful. First couples of month, I wasn't charting BBT, but only aiming day 12-16(not every day).
My cycle has always been 30 days but lately, it is getting shorter 28 last 2 month and this time 26. My last 4 start day is;

8/18(just started today)
7/24
6/22
5/29

I don't remember the exact date prior but I have always been regular, normal bleeding(6-7 days in cycle), 30days cycle. I really want to conceive soon and need to know if I have developed some abnormality in cycle?...  Annual phisical came back normal recently(also last OB/GYM visit oct '03 was OK - low grade displasia was found but currently just monitoring, no specific treatement).  How should I plan now that I am not sure if the cycle will be even shorter next month?  I started BBT chart from last cycle.
Thank you very much for any help...

Answer
From May 29 to June 22 is 25 days. From June 22 to July 24 is 33 days. From July 24 to August 18 is 26 days. You appear to have normal cycles. A cycle is considered normal if it is 21-35 days from the beginning of one period to the beginning of the next period. If you go by the last three cycles (25days, 33 days, 26 days), and you normally have a 30 day cycle, I would assume that you ovulate around cycle day #12-16. I would concentrate having sex every other day from cycle day #12 to cycle day #18. YOu can purchase an ovulation predictor kit from the pharmacy to further pinpoint the exact day of ovulation. If you miss your period, wait seven days and then take a pregnncy test. If you have not conceived after trying to conceive for a full 12 months, you should start an infertility workup. Your cycle is still considered within normal limits and you should be able to conceive.