pregnancy???

so me and my boyfriend are as careful as it gets. I mean he checks each condom befor use, the packaging AND the actual condom, if he thinks that it might have a hole he immediately takes it off. well my breasts and nipples have been really tender and I have been waking up with nausea. I also have been having more cravings and hunger as of late. I think I might be pregnant however I haven't missed a period since my next one is in a week or so. should I wait and see if I miss my period or should I be worried now? I'm only 18 and as much as I love kids and want one of my own, I'm not financially or mentally ready, nor is my boyfriend.