PLEASE HELP!! COULD I BE PREGNANT? I AM SO CONFUSED!

So my SO and I are not trying to get pregnant but we are open also becauee we love each other very much and we are already at that age where we are ready to have a baby. We dont use contraception, only pull out method. But at the end of march we got a little crazy and decided that he will come inside. And then again from April 1 until i have my period. But my last period was sooo weird than usual. It was sooo long. Usually it is only 5 days or 4 days. But it also started weird. April 7 and 8 I was confused because it was pinkish and water like and only a little. So i thought I might be pregnant. And then, April 9 it became my normal period so I thought okay nope. Then 4 days after, April 17, I started experiencing mild cramps and lower back pain like when I feel everytime i am on my 1st day of period. I took a test, but negative. So i brushed the idea off. Thursday April 19 I felt it again, but this time my boobs start to sore a little until now! Took a test again but negative AGAIN! Since 20th until now I was feeling a weird really. On and off mild cramps and lower back pain, sore boobs, feeling a little nauseous after eating, weird discharge, feel sooo hot sometimes like hot flushes but last night i felt super cold when it was hot. And also my SO and I have noticed that my nipples have gotten a little bigger than before. What do you guys think? how many percentage that I am pregnant? Because we smoke and drink so i need to know :( plus we are in a foreign country where not everybody can speak and understand english so mch. Hope yalll can jelp me!!