Could I be pregnant?

This is going to be very lengthy, but for starters I usually have a normal period (7 days or sometimes 5). In Feb my cycle came for 5 days (1st-5th) where I had the high chance of getting pregnant from day 6-10 & my prediction of ovulation was the 8th. My partner & I had intercourse on the 6th or 7th where he finished inside me. On the 9th I took a Plan B around nighttime (mistake I know). My symptoms really began on the 14th and went from there. I started spotting next day (15th) & spotted til the 22nd. I believe I got my period the 23rd & it lasted for 7 days (2/23-3/1) because the flow began to get heavier and I was passing clots. I also spotted the day after my period ended on, resulting in me bleeding for 16 days. All of this was very unusual: a lot of “bleeding”, and two “periods” in one month. During this time & now I have had symptoms ( feeling very sick or not myself, headaches, diarrhea, slight acne on my face, cravings, fatigue backaches/cramps & sharp belly and back pains, tender & itchy breasts/nipples, mood swings: even more sad & irritated) The symptoms have grown more &a sometimes the level increases/decreases. (I cried one time watchin this kids movie &a another lookin at baby pics of my little brother: a little weird) I got my cycle for Mar (3/21-3/27) & I spotted twice in the month.. I’ve been to the doctors like 3 times for pelvic pain & they ran a urine & said that I wasn’t pregnant all 3.. So I read that if you take a Plan B after ovulation then it pretty much won't work, I’ve also read that some women still get their “period”, and some don’t find out their pregnant till some months later, but I’m not sure what to think. Sometimes I just feel off (like sick/not myself) like should I wait or get an ultrasound &a blood test done.. Please help