Pregnancy or not. Could be the reason.

Hi , I just wanted to check ..I recently had intercourse with my fiance but we didn't actually have sex as the part was not inserted into the vagina. Yet the sperm fell on my back and I wiped immediately. During this time it was 5th day of my cycle. In next two days, I went on a trip to North India, where I had to trek uphill and had to walk and go on a horse ride which resulted in body aches and fever. Just after I returned from my trip within 15 days and in the same month I got my periods again. I do get periods 2-3 days early , but this was  too early  and I was surprised to see that I didn't feel cramps like every time I do . After one week of my periods getting over, there is slight bleeding again. Please let me know if this is symptom for pregnancy or what could be the reason.