could i be pregnant ?

In late January-early February I had a period, a totally normal one. On February 11th I had protected sex, but I wasn’t 100% sure so I bought a Plan B 2 days after on the 13th. On the 14th I had what I thought was protected sex but he took it off and he came in me, on purpose. I bought the Plan B about an hour later. I had withdrawal bleeding 10 days after then didn’t get a period for March! Early April I took vitamin c supplements for a few days because I was scared to miss a period, I got it on time but it was lighter than they usually are, filled up a couple tampons but still lighter... on May 7th I got my period again and it’s light just like the last time. Could this be the 2 Plan B's STILL messing with my periods? Or could I be pregnant? I took like 4 pregnancy tests and all came back negative ! i took the first set 10 ish days after my first missed period and another a few days before i got my april period. i have had no pregnancy symptoms. but i DO have low iron and an underactive thyroid... but i take my iron supplements.. what do you guys think