I had cramps since my first month, it’s normal your uteris is already growing and unfortunatley tiliting into your bladder, say hello to immediate bathroom trips no more holding it! I still get cramps at 13 weeks but Im expanding. Now the tired thing they said the first trimester is the worst, im finding out the second is for me, but I was working 70 hours a week during my first trimester, so who knows. If you are good luck, I started having signs from my second week in so I wouldnt doubt it if you already "know" too!