I agree. Your medication should be safe if you are on it now. Just check with your doctor and they should be able to adjust it as needed.
I will soon be nursing my second child, I'm due any day and I have chronic hypertension. You should already be taking a pregnancy safe medication for hypertension and if what you're taking now is not safe for nursing, then your doctor will change your meds after you have rhe baby. Just make sure he or she knows that you are planning on nursing at your next appointment and they should be able to answer any questions you have. My daughter is 6 and she nursed for 8 months and she's just fine. :) Hope this helps.
Ask your doctor or a pharmacist, or go to the website of the specific drug you are taking and see what it says about lactating mothers.