I'm ttc and got a ovulation positive smiley face on May 26th in the night, When should be able to take a hpt?

I'm 27 yrs old and hubby 31 yrs old. I had a miscarriage oct 2009 at 6 weeks & feb 2010 at 4 weeks.I havent gotten my period since Feb 14th 2010. I had with my hubby on the night of May 25tha and also BD on May 26 in the night when I saw the smiley face :). I tested this morning and still smiley face and tested again about an hour ago and smiley :) . When will i be ovulating? Is there a good chance I can get pregnant? When should I take a hpt? Please help :)