HPT issues help please

Ok I don't know if I can explain this so it makes sense and I don't sound crazy lol so here it goes. I've been taking FRER tests and when I took it this morning a crazy looking line showed up right where the first line is suppose to be then is slowly becomes straight and ends up where the control line is suppose to be. Has this happened to anyone and what does it mean? I'm new to TTC so idk if all FRER tests do this or it's just me. Hope it makes sense any help would be appreciated