Cryptic/Stealth Pregnancy

Has anyone had or know of someone who has had a cryptic/stealth pregnancy?

All my tests are coming negative including blood tests but I’ve had symptoms since December. On Wednesday this week I found a heartbeat right under my belly button on the pelvic bone... dead centre. Heartbeat confirmed by my doctor today, waiting for ultrasound appointment to confirm.

I know this is all crazy, but looking for some support. Thanks!