Advice

Hi everyone. My boyfriend and i are trying. I was 4 days late. I saw a little bit of bleeding but i had cramps where i had to take pill 2 times in one day. My flow is normally heavy on second day but it was light bleeding dark red color. Day 3 i saw little to nothing. My period normally last for 4 days. On the 4th day i had to rush and put on a pad in the evening because i started bleeding again and there was no bleeding at night or in the morning and it was a dark red color. Didnt full the pad tho. Today my body feels different i am so fatigue my lower abdomen is hurting so is my back and i have a slight headache. Should i take a test? I dont think i should becauseof the cramps that i felt. Someone told that if it was implantation bleeding then i wouldn't be feeling that amount of pain. I already have a son but i didn't experience this with him while i was pregnant.