Period like cramping?

So im just about 36 weeks pregnant and I keep getting these horrible period like cramps, so bad I can barely walk, and I have a really dull backache, and just this morning I had some brownish dishcharge come out? I have a doctors appointment in about 3 days so im trying to hold out until then but its getting to the point where I dont even wanna get up anymore and my husband is about to go away for work for a week so im going to be alone for awhile. Should I go to the hospital or no?