Debbie,
I don't know what procedure you had done on your spine, whether it was a discectomy or a laminectomy or fusion, but if you have had instrumentation ( rods and screws) put into your spine, there is a possibility of dislodging the screws by pulling or picking up something too heavy.
Where you given any restrictions for post op? Like no bending, lifting or twisting, or weight restriction? If you were, your safest bet is to contact your surgeon and go in for an xray to make sure things are okay. If the pain doesn't settle in a few days, your surgeon may decide to send you for an MRI or CT scan to check on any instrumentation and to confirm you didn't do any damage.
I know that recovery from spine surgery is long and drawn out and especially when you feel better, those restrictions can seem like they are getting in your way, but it is for your protection and your body's recuperation.
Hope you feel better soon...and just give your surgeon a call and try to rest as much as possible.
Sandi