If I can give some advice on OBV, don't get so caught up on one or two indicators that it drives you crazy. There are so many more that could be better for you.
Although I use 13 or 14 at one time, I prefer the Fast Stoch, ADX and MACD along with the CMF. Learn what they all do.
I would suggest that you pull up some charts with as many differnt indicators as you can and draw some vertical lines where the stock you are looking had some upward movement. Then study what those different indicators look like the day or even the week before. Look for patterns, patterns, patterns. And look for patterns within patterns.