I recently bought a mini microscope called Maybe Baby. You place a smear of Saliva onto the glass wait 10 minutes for it to dry and then look into the microscope with the little light. It's brilliant it shows distinct patterns of whether or not you are ovulating. Dots if you aren't and a distinct Fern pattern if you are.
You can use it over and over again you just wipe it with a little cloth they give you. I bought it for 110.00 dollars it seems expensive but it saves