OPINIONS NEEDED (long)

My period is now 16 days late and I am trying to figure out if I am pregnant. My husband and I are not currently trying to conceive, but we also do not take many measures to avoid it. We only use condoms, although not always, but I am pretty good about keeping up with my cycle. I am not currently on any type of birth control and haven't been for many months. I have taken 5-6 at home tests over the past 2 weeks or so and all have been negative. I finally got a doctor's appointment today and they took a urine sample which was also negative. He did not recommend doing a blood test because apparently it can give a false positive. According to him, the urine test is more accurate. I have had some symptoms over the past week including, light cramping, headaches, and frequent urination (I do drink a lot of water, but I still feel like I'm going a lot) almost daily as well as a few cases of heart burn and fluttering in my chest. My appetite has also changed a little. I still get hungry like normal, but I never have an appetite for anything! I'm curios what everyone's opinion is on whether or not I am pregnant and whether I should see another doctor or not. Thanks in advance!