What do you think plz?

Hi guys. so basically after nearly 2 years of ttc after a m/c finally ive got my bfp! Thing is since my m/c nearly 2 years ago my periods have always came when they feel like i ranging from 2-6 odd weeks. the last good few months my periods have been every 6 weeks, that was untill my last period which came after just 3 weeks (since my period before) anyway my last period was the 10th may.. but on thursday 26th may for some reason i did a pregnancy test and it was faintly positive, i then broyght a clearblue with conception to make sure and it said pregnant 1-2 weeks. My question is do you think i may of got pregnant straight after my "period" on the 10th? or maybe my "period" wasn a proper one. i just think its crazy that i found out im pregnant 2 and a half weeks after my last period. Also im so happy as i lost my last baby and since then it hasn happened agan until now.. but i have been getting period pains is this normal? im scared im going to lose this baby to. thanx to anyone who replys, and sorry its quite long.