Prolonged lower abdominal pain

I am a mother of a 13month old. When i was pregnant with him, had some spotting at about the 3rd month of the pregnancy without an abdominal pain.I was asked to take a bed rest.
I got pregnant again and at about the 7th week of the pregnancy i started having this lower abdominal pain with some spotting.I thought i would be like my 1st pregnancy, so i took some bed rest but the pain and the spotting became heavier the next day. I went to the hospital and I was referred to have an ultra sound and the result came out that the gestation period of the embryo was 4 weeks instead of 7 and there is a threatened abortion. I was monitored but the pain and the bleeding became so severe with some lumps. I was examined and told that i have to be rushed into theater for a
D and C.
Now,I saw my period last on the 10th of may and 14 days after, my husband and i tried for another pregnancy but about 2 days after we tried, i started having this pressure,cramp in my lower abdomen with frequent urination usually more at night and back/ waist pain but the pains are just slight but can't be neglected. I am expecting to see my period in 3days time. So i don't know if this is an implantation going on or something else.
Am so scared. Please help %-)