Irregular cycle

So I'm trying to get pregnant I had sex the morning before I ovulated (had lots of egg white discharge) I'm typically on a 28 day cycle but as of the last 3 months it's been 23 27 and 25 day cycle so off course my app averages it out and say my next cycle will be in 25 days (this coming Tuesday ) so I took a test this morning (3days before missed period) and it came back negative but I swearrrr I'm pregnant ! Is it possible my cycle will go back to a normal of 28 or at least 27 days and so the true assaults could alter since I'm goin off of 25day cycle ?!