Ectopic Pregnancy questions

My husband and I are in or first month TTC and since I always worry about everything, naturally why wouldn't I worry about that 😏 I just started my period today and have normal cramping mostly in the right side but nothing severe.. I over think EVERYTHING. Ugh
Anyone who has experienced one, how did you know, and was it obvious something was wrong?!
Is there any of you that didn't find out and had an emergency situation?!
How common are they?
Thanks in advance for helping the paranoid lol!