Trying to get pregnant, could i possibly be pregnant?

So last week on monday and thursday me and my husband had we are trying to get pregnant. And the past two or three days i been feeling like i have to poop and when i try to go nothing comes out i hear constipation is a sign of pregnancy is this tru? So its been a little less then a week but im still not morning sick and my dont hurt how far along would i be to feel these symptoms? is there a chance i could be pregnant?