Dark red blood

So I'm 4 weeks and I'm experiencing spotting like a dark red sticky. I don't have any other symptoms besides that no cramping nothing. Possible mc? Idk what to think u feel it's pointless to ask the doc because if it is a mc there's nothing they can do this early. I did have sex yesterday and this was supposed to be the week I was supposed to get my period. I just found out I was pregnant on Sunday. Help I'm scared ! I got a knot in my stomach 😞😞😞😞