Surface water movement takes place in the form of currents. Currents move ocean water horizontally at the ocean's surface. Surface currents are driven mainly by the wind. Other forces such as the Coriolis effect and the location of landmasses do affect surface current patterns.
If the line is darker I would assume a BFP. Normally as Ovidrel leaves your system the line will get lighter. I was told by my doc that it could take at least 10 days to leave your system...which is why we're not suppose to test before day 14 (like any of us can wait that long). Congrats and best wishes to you!
Your best bet is probably to use an ovulation predictor test. If you've never tried an ovulation predictor test (or OPK, ovulation predictor kit), they work a lot like pregnancy tests. You pee on a stick, and the test will indicate whether you're in your fertile window or not. You can start taking the OPKs the day after you finish your Clomid pills.