extremely stressed

I haven't gotten my period in about 2 and a half months and I haven't really had sex either let alone unprotected sex until more recently i had PROTECTED SEX with my boyfriend. He came and took off the condom and we stopped for a bit until we began to fool around again for him to put it in without a condom and without using the bathroom but it was only for a very very short period of time. This was last week ( around 6/16) and today it is (6/23) and i have been getting slightly nauseous in the morning but that may be due to lack of sleep. I also noticed spotting a few weeks back but never actually got my period. I really mever got my period regularly and I am far from ready for kids and I am extremely stressed about this situation. Please give me insight!!