 [ Symptoms ] effectiveness of birth control my girlfriend 18 years old takes her pill exactly on time every single day within 3 minutes of her 900pm time never any later we have unprotected sex we have already been tested and have no worry of stds and i ejaculate inside of her although she takes her pill exactly on time every single day is there a chance that she could become pregnant [ Disease ] if you have heart problems and recently underwent a procedure i would recommend first that you check with your cardiologist to make sure it is safe for you to engage in sexual activity if your doctor thinks it is safe you can take viagra while taking blood thinners you would need to avoid viagra if you were taking any medication in the nitrate class like nitroglycerin or isosorbide dinitrate which are taken for chest pain and angina