This transabdominal pelvic ultrasound demonstrates a single, live IUP with a fetal heart rate of 146. It is evident in this clip that there is a hypoechoic fluid collection on the right lateral aspect of the uterus between the uterine wall and the chorionic membrane, consistent with a moderate sized subchorionic hemorrhage. There is no free abdominal fluid noted.
Take home points:
Subchorionic hemorrhage, present in 3% of pregnancies, increases the risk of fetal complications. 
spontaneous abortion (from 8.9% to 17.6%; OR 2.18, 95% CI 1.29–3.68)
stillbirth (from 0.9% to 1.9%, pooled OR 2.09, 95% CI 1.20–3.67)
abruption (from 0.7% to 3.6%, OR 5.71, 95% CI 3.91–8.33)
preterm delivery (from 10.1% to 13.6%, OR 1.40, 95% CI 1.18–1.68)
preterm premature rupture of membranes (from 2.3% to 3.8%, OR 1.64, 95% CI 1.22–2.21)
Patients who are noted to have a SCH should recieve the appropriate dose of Rhogam if Rh negative, even in the absence of vaginal bleeding.
The providor should arrange close followup with patient’s OBGYN to follow the hematoma until resolution.
The patient should be instructed to have pelvic rest until cleared by her OBGYN. 
Some sources recommend bed rest, although this has not been proven to improve outcome. 
1. Tuuli MG1, Norman SM, Odibo AO, Macones GA, Cahill AG. Perinatal outcomes in women with subchorionic hematoma: a systematic review and meta-analysis. Obstet Gynecol. 2011 May;117(5):1205-12. [article]
2. DeCherney A, Nathan L, Goodwin TM et al. Current Diagnosis & Treatment Obstetrics & Gynecology, Eleventh Edition. McGraw Hill Professional; 2012.
3. Snell BJ. Assessment and management of bleeding in the first trimester of pregnancy. J Midwifery Womens Health. 2009;54(6):483-91.