I had after that...?

a week after my period went off i had , but the condom popped. He said he immediately pulled out, but that was 6 weeks ago. Ever since then i've been felling sick, tired, and nauseated but i think it's just stress. I am not really worried but i don't think i am. I took a test it cam back negative and that put my mind at ease. But i am still experiencing symptoms. He doesn't want a child right now and neither do I. So i have been thinking a lot about abortion. What should i do?