Has anyone used this before? I got a solid smiley for the first time yesterday  after having a few days of just O as the reading. Is it notmal to not get a flashing smiley leading up to the solid one? After i saw the solid smiley yesterday, the display never went away...is it broken? The box/ instructions doesn't  address this...should i keep testing till i get an O reading  again or should i stop till next month? Should i still keep having sex?