hello,
first of all, you wouldn't be able to feel any sort of fetal movement until at least your 4th month of pregnancy, and even then some woman don't feel it until closer to the 5th month.
i am currently 15-wk's pregnant, with a small build, and have yet to feel any sort of fetal activity. i should be feeling something within the next couple of weeks. i also have not felt the baby's heart beating through my own skin, but i have seen it on an ultrasound.
secondly, the only way to know for sure as to if you are pregnant or not is to take a home pregnancy test, then depending on the result, follow it up with a blood test. a blood test if more accurate than a home pregnancy test. it would also be a good time for you to set up an appointment with a doctor, especially since you have a health problem which could cause infertility. it might put you at a greater sick of miscarrying. i don't know your condition, so i couldn't say exactly.
lastly, if you are pregnant & you are feeling the baby move, then you should seek immediate medical attention. it's not good to let your pregnancy go on that long without proper care. you should be seeing a doctor by the 8th week of pregnancy & continuing to do so until your child is born. prenatal vitamins are a must in the early weeks.
i wish you the best of luck, keep us updated.