It can feel like your period when you have conceived.
My sore boobs started off with just tender nipples, I was lightly nauseous and had lower abdominal cramp and lower back ache. These symptoms were all very similar to my normal PMT.
However I knew that things were different because I had seen the implantation spotting about 7 days after my temperature went up, which made me totally obsessed about being pregnant so every single symptom I had after the spotting made me feel even more pregnant. Also my sore boobs were getting worse and it wasn't just the nipples it was all over. I was also starting to get very tired as well.
But yes, the majority of my symptoms were very PMT like