What Causes Stomach Bloating And Breast Tenderness After Finishing Periods?

Hello
Me and my boyfriend were dry humping on my ovulation day he had his boxers on and I had my panties on ( both are virgins) with no penetration but he did pre-ejaculate on his boxer . I waited 10 dpo to do a hpt and got a negative then I think I got my period but it only lasted for 3 days I am afraid it is implantion bleeding after the bleeding stopped i tested my urine again it is negative. My period is after 3 days I am bloated , tender breast and urinating frequently. Am I pregnant ? Please help!