Going to sound crazy

So i took an ovulation test. a few days before it said neg. On the 30th of Nov it said positive. We had sex 2 days before this, the day of, and two days after. I feel like my odds of getting pregnant are good this month. On the 3rd of this month (and everyday since) my boobs are really sore. I have severe acid reflex, headaches, slight nausea, slight back pain and cramps off and on. I know it's going to sound crazy but can anyone tell this early if your pregnant. 3 days and symptoms seems odd. I have been pregnant before. (miscarriage) and these are the same symptoms. Has anyone else had symptoms within the first week?