Is this the start of my period ???

My period is more then 40 days late. So I’m so confused. I took a pregnancy test when I was two days late and it was negative. My dr took a blood test when I was 3 days late it was negative. Now at 10 am I had two little dots of blood and when I went to the bathroom I had a little but that is all and it’s 1pm. I normally bleed pretty heavy. I’m confused.....I cramp every once in a while . Also I do have pregnancy symptoms like cravings, cramping, tired and nausea. Also my boobs jumped for 36c to 36d almost a DD. I don’t know if this could be the start of my period or I could be bleeding because I am doing heavy lifting at work today. What should I do ?????