What can I do for false pregnancy symptoms if I don't have a doctor yet?

Nothing No Worry. If you really have a false pregnancy then you do not need to do anything. The question is whether you really have a false pregnancy. I do not know enough to give specifics but i think that this diagnosis usually suggests the need to get professional help, just not urgently. Start with gyn or pcp to get diagnosis then on to specialist if necessary.
Flase positive test. It is often due to antibodies in your bloodstream related to exposure to rabbits, mice, pigs etc. It can be related to a non-specific activation of your immune system. The first step is that you physician will check for pregnancy using different tests and run the test at various dilutions of your blood. They should not on the request to check for false positives which is a separate lab procedure.