The pregnancy test result is making me feel insecure.

Hi ladies...

Normally I'm not quick to ask a question on a forum myself, but this time I'm so unsure and confused that I'm giving it a shot anyway....

Here's my story in brief:
Last period: 5 days late, then I got a light bleed that didn't look like my period at all.. I also had vague early pregnancy symptoms...
Because of the bleeding, I stopped thinking about a possible pregnancy since a test told me I wasn't pregnant.... Now I should have gotten my period again about 5 days ago.... I took another test last night with a Clearblue Digital.... It quickly said 'pregnant'...
I was so happy with that... Today I thought I'd play it safe and do the other test I had lying around too... And again: 'pregnant'....
Since I'm confused about the previous 'missed' period, I wanted to know how long I'd already been pregnant.... So I quickly went to the pharmacy for another Clearblue Digital with indication....
Now I take that test and it now shows a -, negative then.... This is really maddening....
I've already booked an appointment with the GP for next Friday... We're leaving on a trip on Saturday too... I really can't relax while living in this uncertainty...
Has anyone else had this kind of situation?
Thanks for reading my post in advance. .

Best,