Cramping 4 dpo? too early for symptoms?

So last month had a chemical. This month I did the opk on Wednesday and it said low, Thursday morning it had me at peak! Making me about 4-5 dpo. Had O pains on the left and yesterday I had some cramping on the left. Woke up in the middle of the night to cramping on the left but it went away immediately.  Today I'm cramping again on the left. I'm dying to test but I know it's too early. I can barely stand to wear a shirt without a sports bra - too sore. Anyone get cramping and similar symptoms  like this and then get a bfp? Just curious! I know everyone is different