Another idea is that your husband does not just float by and deposit some sperm in you, the two of you have to do something rather active to get it in there I assume. Possibly something about the muscle movement involved (for you) is causing muscle or heart pain? You could test this by giving him an out-of-the-body experience (so to speak) with your hand, and then tucking some of the semen into your vagina, and then wait and see if the same chest and stomach pain happens. If it does not, you could then try to mimic some of the body movements you do during sex, and see if *that* gives you muscle pain. I would guess it is something about the physical straining that happens in sex, rather than an allergic reaction to sperm.
Hi there. Hm. Well, I do know that some women can be allergic to someone's sperm. But that is usually described as a burning or stinging sensation in the vaginal area. I would see a doctor for this concern. good luck