How painfull are abortions and am i doing the right thing?

im going in sunday for a tablet and then tuesday all day for the abortion,ive never had one before but want to know what happens?im not 100% i want to do it but i feel i need to,i already have a 4year old from another partner,ive only been with my new partner 8weeks and im 6weeks pregnant.please dont judge me i need advice,thanks