bfp and so nervous

Hi - I am 11 dpo and been trying for almost 6 months and literally thought I'd have no chance this month and this morning this happened! And I cant help but feel it's a false positive ?! Doubt is creeping in sooo bad. I will do another test tonight but did anyone have similar concerns? Do I just have to wait it out until AF definitely doesn't show and keep testing along the way? I'm sorry if this sounds insensitive to people waiting for their bfp. I know it's hard but I can't believe how much doubt I have ... it has shocked me!