I hope you know that the days of your ovulation period are not the same every month. Typically, you ovulate about a week after your period.
There are three ways to check your body to know you are ovulating. There are also little microscopes you can get at target for like $13 that magnifies your saliva (which changes appearance depending on how fertile you are or or not because the increase in hormones changes the structure of your saliva).
Also, it is really likely that a hormonal and nutritional imbalance is keeping you from having an ovulation period that allows you enough time to actually conceive. A friend of mine took some supplement called ovulex and she was pregnant on the next cycle, no kidding. Pretty much she just had some imbalances and it helped her get balanced and made her body a perfect environment to conceive. I have another friend who takes it just because her pms symptoms are *awful* without it. It's totally natural (you don't have to get a doctors prescription or anything).
If you haven't been to a doctor to find out what might be preventing you from getting pregnant, you should. (maybe you only have one ovary so you have half the chance of getting pregnant? This is totally unlikely but if you haven't seen a doctor yet you wouldn't even know...)
if you have been to a doctor, don't get to discouraged yet. There are things you can try before draining your bank account for in vitro fertilization or other risky things like that.
If you want to know how to tell when you're ovulating let me know. It's pretty straight forward, especially once you get it.
It's actually pretty hard to get pregnant. Usually girls that don't want to but do only do because they get hot and bothered when they're ovulating because of the hormone changes. But there is only a window of like 4 or 5 days during your entire cycle when you can actually get pregnant. And after that, usually 1 in 4 or 5 women will miscarry because the embroy is a foreign body to a woman and the white blood cells will try to destroy it. Pretty crazy. Most survive and continue to grow to full term. But miscarriage is way more common than women think. When it does happen, though, it usually happens pretty early on. When it happens later, something was wrong.
What the other post said about your husband's ejaculations is correct. The more he ejaculates, the lower his sperm count will be. You want to make sure that you do *not* have sex every day while you are ovulating, but wait until the last day or two. It's nearly impossible enough already for one in a bazillion sperm to penetrate the ovum (egg) and chances are even more slim when there are even less sperm.
Some women have gotten pregnant from being on top. Others have tried for months and only got pregnant on bottom or from behind, and then elevating their pelvis (with a pillow or two) for an hour or so after sex. The positions and elevation help the sperm get right to the cervix (at the very top of your vagina) to give you better chances of getting the most into your cervix and into your uterus to find the egg and fertilize it. Also, if you have sex before you ovulate you will not get pregnant because before (and after) you ovulate, your cervix is plugged with a mucus. When you are about to ovulate, your cervix softens, widens and raises up. This releases the cervical mucus which, by the way, makes the vagina a very fertile environment (when the mucus plugs the cervix, which is most of the time, the vagina is a very acidic, hostile environment for sperm).
I know that's a lot of info. I hope it helps. Like I said, let me know if you want to know how to tell when you're ovulating, not just guess dates.