I feel like a first time mommy but im not

I have a 7yr old daughter when pregnant my only sympton was constantly throwing up..

Have a 5 yr old boy and with him no symptons found out i was pregnant at 4 months..

Just on 12 dpo i got 4 bfp reason which was on the 11th of december my period was due on the same day and of course no af so of course im expecting how i knew was the cramping on my lower back and tummy felt like period cramps,i yet havent gone to the hospital because my masshealth isnt yet active but surely today i will make an appointment...Anyways in the last 2 days i been getting shooting pain on my lower back its kinda scary is this normal? I never felt this with none of my pregnancies but i am the lead server at olive garden i do alot of heavy lifting and i work 4 doubles Thursday-Sundays thats 12:30-9pm shifts should i be worried ? Has anyone experienced this pain?? If im adding right my last period was nov14-the 21st..so what im about 4 weeks or less...Im a confused mommy to be please help These are my 2 love bugs