Freaking out

I am freaking out. I had my Mirena removed on 26 June. It has been exactly one month and I took a test today (because I’ve been feeling off) and there is a very very faint line. Is this possible? It took us 22 months to conceive our last. I was having a not so great time with the Mirena. We took it out hoping to try something else. We have 3 children. I definitely wasn’t trying to get pregnant but we obviously did nothing to prevent. I am just in disbelief. I’m 35 years old, and the old mentality of 35 being too old is messing with my emotions. I will continue to test to be sure this is real before making an appt with my OB.