I know it's invalid BUT...

Hi guys I took a FRER this afternoon, eve says my period is due in two days but I know I ovulated late so probably around 5 days till it's due. Have been feeling 'off' so took one for fun... I saw a vvvvvvfl couldn't tell if it was imagination or not so I took the test apart and saw a line. I know it's invalid but that hasn't happened to me before, everytime I've taken it apart there's been no line except today. What do you think?