could i be?

My fiance and i have recently been having and sex and well.. ive let him climax inside me a few times, and im a little nervous because it was during my monthly cycle and a a day or two before and after it.. how possible is it that i could be pregnant? i mean, i would be completely estatic if i was, i want a child but im not so sure im ready to give the baby a good life, as with work and school still living at home.. that whole thing. someone help :[