Possible pregnant??

So for the last few weeks Ive been really nauseous most times when I'm hungry but all the time when I go to bed I get cramps in my lower abdomen and I get a really sensitive nauseous where I feel like I'm really going to puck. Ive also had really sensitive nipples and tender breast. I went to the drs and they told me I wasn't pregnant. Also Ive had a lot of cervical mucus and it's been really stretchy. Also I have cravings for weird things and then I eat them and immediately feel nauseous, and I have been getting heartburn like crazy and have never had it. Somebody help!!!! 😞😞