Need advice..anybody who is pregnant or has kids...?

well if i was pregnant i would probably say im 4 weeks pregnant...im so confused cause i here from alot of people that while you pregnant most women can still have their period except its not really called a period..it spotting...but mine was alittle lighter than usual...and lasted five days....after that..i still was cramping..and in the mornings, it be feeling like i gotta throw up but i dont....so im kinda wondering whats happing.. can anyone tell me how many weeks it usually take to start felling symptoms..??