Can ovulation and pregnancy happen without a LH surge detected?

Those tests don't work for everyone, so I wouldn't panic. Have they worked for you in the past? Generally, going by tring while you have EWCM or just prior to a temperature surge is better than going by an OPK. Maybe try doing one of those things in conjunction with your test. While its possible you didn't ovulate this month, those tests are not fail proof, nor are they gospel. Keep trying and if not, there is always next month? Taking temps was good for me because it helped me figure out after about three months that my body was not working properly. The doctor took one look at them and put me on a slight dose of Clomid. That first month of Clomid, we conceived! It saves a lot of frustration to have those charts available for the doc to avoid months and months of trying to no avail. Check out fertilityfriend.com for charting istance. It worked for me! Good luck.