Throat infection from kissing some somebody new? iin?

I find this odd. When I got my first boyfriend, we shared our first kiss and suddenly I got a throat infection. Time went by I was fine until he went to Vancouver for 10 days, when he came back I got another infection. Time goes by..we broke up..we moved on, I thought I found somebody, we kissed, throat infection next day. Things didn't work out..time goes by, I kissed somebody that didn't give me a throat infection:)... After time, things got rough and we decided to go our separate ways. Kissed somebody else, mayor throat infection. I don't get it. I have good oral hygiene, & so did the other guys. Ive gotten a few throat infections from other things, mostly in the winter. When I get a sore throat it automatically turns into a throat infection. I've been to the doctors about it for antibiotics and they didn't say much about it. That viral infections were very common. I just don't understand why I keep getting them so often. Anybody have any suggestions?