Family Planning Plus

I am not sure that there would be a direct link between ejaculation and your dry heaves. If your partner is performing vigorous thrusting during intercourse, the pressure against your cervix/ vagina may be stimulating a nerve reflex. It may also be related to anxiety, excitement or fear.

In researching this, I did find that, although this reaction is uncommon, you are not alone. There are others who have this reaction with both physical and sexual activity. If this is affecting your daily life/relationship,  consider making an appointment with your primary care doctor. You first want to rule out an physical cause (like reflux).