What are early pregnancy symptoms?

Hi, has anyone else experienced bad cramps in early pregnancy? It’s in my whole stomach and lowers back. I have had these cramps for a while now already, probably for about a week or maybe even a bit longer. I’m 22dpo and just got my faint positive today in the morning, and now I’m a little worried about the pain since it’s quite intense. So just curious if I should be concerned or if anyone else has experienced it, and all was fine. I was thinking maybe gas pain, but then I probably wouldn’t have it in my back, right? And Being on my feet makes the pain worse or if I move suddenly or fast, and my legs also have been getting so tired that by noon I have just no power in them it literally feels like I walked a marathon, and by the end of the day the pain from in my lower back has gone into my legs.