28 days late ๐Ÿ˜

My period is 28 days late. I started the pill a week before my last period and got it right on time and since then ive had no bleeding at all. I did have unprotected sex 2 weeks after starting bc and have taken 2 tests (one at 3 1/2 weeks and one at 5 weeks after) both bfn. Just the pill stopping my periods?