sperm throwing off ph

I tried to explain to my sex partner that semen is throwing off my ph. he has came in me at least 3 times last month and I am currently 7 weeks pregnant. all of my std test came back negative so that has to be what it is. i’m pretty sure I have bv. I spoke with my doctor and had a swab done and they didn’t tell me in the office if I had it or not like usual. I guess they’d call me when the results come back. but this is normal correct? I just want him to understand that. so I told him he couldn’t cum in me anymore i’m tired of my balance being thrown off.. he seems a little upset about that.. I was gonna let him do it bc i’m already pregnant but idk now.. when it’s treated if I take probiotics daily and eat plain yogurt will it help keep it balanced if I let him?