What the heck just happened

Ok so I test for oveilation every morning and night (please exuse the spelling I am working with one contact) ( that is for a different post all together) so for the past few days I was getting not yet lines then yesterday I got the go lines so we baby danced all day. Then that night the line was gone...... Like completely gone and I took 3 tests to make sure it wasn't a glich. What the heck just happened lol and I have been feeling all crampey and low key alittle sick. (Not sick but do you ever just feel like your sick yeah that sick)