Am I pregnant?

Jess
So here is my confusing experience.
I had some pregnancy symptoms and got told to do tests as I wouldn't be able to get an appointment or blood test until the end of January.
I did tests, I got a positive, a bunch of invalids and then a negative. All done at different times and different days and weeks. 
Has this happened to anyone? Just looking to know as it would probably put my mind at rest.