How many dpi am i

Gdm ladies đź’—

I’ve been tracking my opk after my period because i do not know when i ovulate . On 1/28 i got a blazing positive . How many dpo am i because i use several apps . One is saying 6 dpo , 7dpo . Can some one tell me the correct dpo 🤦🏾‍♀️ I’m having mild cramps this morning .