1) Is it true that taking those Emergen-C packets or any other vitamin supplements can effect the effectiveness of your birth control pill?

2) I know antibiotics can lower the effectiveness of birth control, but can probiotics or prebiotics, such as a floral acidophilus FOS, also decrease effectiveness? I've been taking birth control pills for the past 10 years with no scares or baby bumps, and I don't want to wake up pregnant one day because I took a capsule that's supposed to be healthy! :)

First, I'd like to thank you for this service! It's been so informative to read the advice you've given others. I'm a female grad student and have just gotten into a relationship for the first time. I have a few questions regarding oral sex: my boyfriend loves to suck my nipples and I feel great when he's doing it, but after a while, my nipples start to feel tender and actually hurt sometimes... is this normal? He's not rough when he's doing it, so I'm not sure why this happens.

Also, when my boyfriend "goes down" on me, I worry about what he thinks of my smell and taste. He says he likes it, but I can't be sure... is there some way of finding out if my scent is normal? Can he pass any infections (to my vagina) from his saliva? (He has had only 1 one-night stand affair and he used a condom that time).

Also, I masturbate him (I stroke his penis) until he "comes," but I'm afraid of tasting his "come." He hasn't asked me to, but I think he would like it if I did... how can I overcome this inhibition? Are there any risks for me? I appreciate any help/advice... Thanks a lot!

I was just wondering about the difference in effectiveness between "ultra sensitive" and regular condoms. I imagine there is a greater chance of breakage with thin condoms, right? Sorry if this is a silly question, but for some reason, I thought I heard that there wasn't a significant difference.

I have encountered a problem I never expected; my boyfriend is quite simply very large. I am unable to perform oral sex except for the first couple of inches due to the girth, and vaginal sex is not totally satisfying for him because he is too long and cannot fully penetrate without causing me significant pain. I've seen my doctor, and am reassured that there is physically nothing wrong with me — no infections or scarring, but am finding it difficult to come up with a solution. Any suggestions?