Coming down with a cold or mono?

okay, my cousin has mono and 3 days ago she bit of a small piece of pizza an put it into the refrigator, i didnt know it was hers so i went an warm it up and ate it but that same day i went to work im a pool attendant so it was cool outside and rainy i been out there since 10:30 to 7:15pm during the time i was there i was sniffing and sneezing and later that night i was cold and had chills but the next day my throat is itchy and dry and my ears itch too i went to da doctor yesterday and i explained to her everything i just wrote and she said im fine i dont have mono but she didnt test me for it she just looked in my mouth and my mom says its all in my head just because i bit off pizza that was hers doesnt means i have it she also said that can only be spreaded through salvia...so can i just be coming down with a cold because i was out in the rain and cold for almost 7hrs or can it be mono coming??? thanks in advance for your opinion..