With my LO and this pregnancy we conceived using preseed (first month of using it with LO and second month of using it this time.Also ov tests and the 'sperm meets egg plan' both times too,sperm meets egg with preseed worked both times first month of trying these two together,after about 4 months in each case of ttc without these.
Carefree and young I know it can be frustrating but sometimes you just notice things a lot more once you start ttc,also randomly it does seem like lots of BDing and TTCing seems to have odd effects on women's hormones,there always seem to be a lot of women on the boards who once they start ttcing are late for the first time ever without being pregnant or their periods change or they have symptoms they never had before,although this could be either a hormonal change or just that we notice absolutely everything when ttc.
Try not to fret and maybe try some of the tips above,ov sticks (even the cheap ones off ebay) can be helpful to determine the right time in your cycle as can charting/temping,a calendar alone only gives you a rough estimate based on an average woman's cycle pattern.
Hope that helps!
