Plz help i may be pregnant!!?

K here it goes I'm may be pregnant. I have always had irregular periods though so I can't really tell that way. I'm 21 and currently buying a home with my husband to be. we have been having unprotected since October 6 09. And havent got pregnant yet so I think . I'm suppose to start around the 17-20 if i even do every month. I have been tired lately but I also started a new job to but I've been doing this kind of work for 2 years so I don't know. Two weeks before memorial day I got off my period but on memorial I drink a beer and went to the bathroom and had like a light brown discharge then the next day it was light blood and then stopped so thats when i was worrying. Then today jun 28 I spotted a bright pinkish red blood but really light it was just one wipe and it was barley on the toliet paper then it was a light brown. And for the past week i have been having Sharp pains around my hip bones. my mother also had that when see was pregnant with me n didnt no it they thought she had somthing wronge with her so it my be hereditary. I also get really emotional easy. thx for your help sorry it was soo long. thx for taking the time to read this have a great day and god bless