Pregnant?? Help!

Tricia • 20 • ER Tech
Last month (first month on the pill) I got my period after the placebo/period week. This month's placebo week started yesterday....still no period. In the past, I've always had my period on this week. Should I be expecting it this week or next? I didn't do so well with my BC pill this month and am having lots of new and some old but exaggerated symptoms in the past week. So I'm beginning to wonder if I should get some pregnancy tests. What do you think?? 
Thanks in advance!