My partner did not cum into me, and his penis did not fully come in-pregnant?

On December 13, my partner and I started to have sex, but I stopped him because i was not ready(condum, birth control pills, etc). We both are certain for sure that he did not ejaculate into me, but not so on precum. The next day he tried ejaculating himself to see how he felt; to see if he could feel it when the precum came. He did not feel the same way when him and I started to have sex. My period last month began November 22, and this month it began exactly the 22. We were both relieved when it came, but then i was worried if possibly this bleeding is implantation bleeding, meaning i am pregnant. The first three days of my period were not heavy, but the normal amount for me came, but yesturday there was almost nothing, but the blood was still red(not pink, or brownish), and today, in the morning it was like yesturday, but now it's nothing. It could be that my period is over already, but I mostly last up to the full 7 days, but i have lasted only 5-6 days with my period. Is it highly possibly that I am pregnant, or is my stress, and sickness(actual cold for past two days) are making me go crazy over nothing?