I am hypothyroid. Started take eltroxin this month. I had severe cramps with my period I even took tamol to ease the pain and it is just spotting?

Since you have. Only been on thyroid replacement for less than a month, and it takes a full 6 weeks to reach equilibrium in your system and then be tested again to see if it's the correct dose, some of your symptoms may be due to improvements in hormones with correction of the thyroid deficiency. If they worsen, however, or don't correct w/further therapy, inform your doctor.