Hi..as you have performed unprotected sex, and had a bit different bleeding episode, first step i would suggest you is to perform a urine pregnancy test (upt) by self at home..if positive,get an urgent transvaginal ultrasound to confirm the site and viability of your pregnancy ( as bleeding might be normal implantation bleed but might be a sign of miscarriage or ectopic pregnancy).. If your upt comes out to be negative, then get a serum TSH and serum prolactin done and keep your menstrual charting..start taking syrup evecare/ menoreg..if menses persist to be irregular, further gynecological evaluation and oc pills may be required to regulate your cycle.