Help! Confused !!!

K so ive been taking tests every day for 4 days all negative but i have pregnancy symptoms this will be baby 4 and pregnancy 9 we have been ttc for 15 months. So took one fmu this am looked positive but wasn't sure it was light well saw it again a few hrs later (i know i know not supposed to look) but it was a thick dark line the others never changed! So went snd got a diff test and took it idknif theres somethjng there or not... whats going on???