Sex 4 days post breast augmentation. Am I in danger or at risk of hematoma?

Thank you for your question and I am sorry that this has caused you to be worried.  Though it is not advisable to have relations this quickly after surgery, if there has not been any significant change to your breasts' appearance - rapidly increasing size, worsening pain, bruising - all is likely well.  

In general I tell patients to avoid sex, exercise, or strenuous activity for about a month to limit the likelihood of postoperative problems.  The main concern is if any changes in the breasts occur.  My patients know to call me immediately if they notice new postoperative pain, asymmetry, or swelling in the breasts.Best of luck,Keith BlechmanNew York, NY