Is Heavy Bleeding With Weak Legs In Menstruation Normal?

i took the morning after pill 2 weeks ago. starting this spotting bleeding thing on and off.felt at times i was hit by a bus fatigued,lower back bothersome and lower ab bloating and discomfort. thn a few days later i thhink i got the real time of the month for 3 days. is this going to go away? i went to my gyn and she said everything was fine and normal.but i dont know.. ive been reading online and ive been getting myself nervous. today would be the 3rd day with my period and im having red blood and seems like more than yesterday at times.i have my legs up because i feel weak.should i go to the er? see a doc? its sunday.