Can you have caffeine free soda first trimester?

i might be pregnant and I've been trying for awhile. i was wondering if I could drink caffeine free soda like Ginger ale? and another thing I know it's kinda weird but my husband wants oral lol and he likes to come in my mouth would that affect me since I might be pregnant? yeah I know it's pretty embring to ask that question but I really wanna know since we've been trying alot.