7dpo backache, nausea and sore breasts

So I woke up this morning, and while I was up and moving around this huge wave of nausea hit me and my stomach started feeling tight! I almost ran back to the bathroom! Then my lower back starting aching. It's still aching pretty bad and my stomach still feels tight and my breasts are incredibly sore (have been since yesterday). Yesterday afternoon my lower back ached + slight cramps for just a few minutes. What do you think?