I might be pregnant. Any advice?

Okay so.... I feel that I may be pregnant. My period is usually very regular. I start at the end of each month. Last month I started at the beginning because I have been so stressed. This month it hasn't started yet and I'm a little confused. I started getting lower back pains and cramps like I would any period. The only problem is it won t start and this has been going on for a week. I took a pregnancy test and the line was very very faint so I can't tell what it means. I don't know what any of this means. Should I take another test or wait till the end of the month to see if my period starts? Help?